Catalyst systems and polymer resins having improved barrier properties

ABSTRACT

A unimodal polymeric resin having a density of from about 0.946 g/ml to about 0.97 g/ml and a zero shear viscosity of from about 8×10 2  Pa-s to about 6×10 4  Pa-s. A method comprising (a) providing a catalyst system comprising a half-sandwich transition metal complex; (b) contacting the catalyst system with an olefin under conditions suitable to form a polyolefin, wherein the polyolefin is unimodal; and (c) recovering the polyolefin, wherein the polyolefin has a density of from about 0.946 g/ml to about 0.97 g/ml and a zero shear viscosity of from about 8×10 2  Pa-s to about 6×10 4  Pa-s. A unimodal polymeric resin having a density of from about 0.946 g/ml to about 0.97 g/ml and a CY-a parameter of from about 0.5 to about 0.6.

CROSS REFERENCE TO RELATED APPLICATIONS

The subject matter of the present application is related to U.S. patentapplication Ser. No. 12/890,455, filed concurrently herewith andentitled “Novel Catalyst Systems and Polymer Resins Having ImprovedBarrier Properties,” which is hereby incorporated herein by reference inits entirety for all purposes.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

THE NAMES OF THE PARTIES TO A JOINT RESEARCH AGREEMENT

Not applicable.

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not applicable.

BACKGROUND OF THE INVENTION

The present disclosure generally relates to catalyst systems and polymerresins prepared using same. More particularly the present disclosurerelates to the use of catalyst systems comprising half-sandwich chromiumcompounds to prepare polymer resins displaying improved barrierproperties.

FIELD OF THE INVENTION

Polyolefins are plastic materials useful for making a wide variety ofvalued products due to their combination of stiffness, ductility,barrier properties, temperature resistance, optical properties,availability, and low cost. One of the most valued products is plasticfilms. In particular, PE is the one of the largest volume polymersconsumed in the world. It is a versatile polymer that offers highperformance relative to other polymers and alternative materials such asglass, metal, or paper. Plastic films such as PE films are mostly usedin packaging applications, but they also find utility in theagricultural, medical, and engineering fields.

PE films are manufactured in a variety of grades that are usuallydifferentiated by the polymer density, for example, low densitypolyethylene (LDPE), medium density polyethylene (MDPE), and highdensity polyethylene (HDPE), wherein each density range has a uniquecombination of properties making it suitable for a particularapplication.

Despite the many positive attributes of PE, the film product remainspermeable to moisture (e.g., water) and/or gases such as oxygen andcarbon dioxide. Thus, it would be desirable to develop a PE film productexhibiting improved barrier properties. It is of further interest todevelop novel catalyst systems capable of producing polymer resins thatcan be formed into films displaying the aforementioned desirableproperties.

BRIEF SUMMARY OF THE INVENTION

Disclosed herein is a unimodal polymeric resin having a density of fromabout 0.946 g/ml to about 0.97 g/ml and a zero shear viscosity of fromabout 8×10² Pa-s to about 6×10⁴ Pa-s.

Further disclosed is a method comprising (a) providing a catalyst systemcomprising a half-sandwich transition metal complex; (b) contacting thecatalyst system with an olefin under conditions suitable to form apolyolefin, wherein the polyolefin is unimodal; and (c) recovering thepolyolefin, wherein the polyolefin has a density of from about 0.946g/ml to about 0.97 g/ml and a zero shear viscosity of from about 8×10²Pa-s to about 6×10⁴ Pa-s.

Also disclosed herein is a unimodal polymeric resin having a density offrom about 0.946 g/ml to about 0.97 g/ml and a CY-a parameter of fromabout 0.5 to about 0.6.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph of the molecular weight distribution of polymersamples from Example 1.

FIG. 2 is a plot of the radius of gyration as a function of molecularweight for the samples from Example 1.

FIGS. 3 and 4 are graphs of the molecular weight distribution of polymersamples from Example 2.

FIG. 5 is a plot of the moisture vapor transmission rate as a functionof zero shear viscosity for the samples from Example 2.

DETAILED DESCRIPTION OF THE INVENTION

Disclosed herein are catalyst compositions and methods of making andusing same. In an embodiment, the catalyst system comprises a transitionmetal complex, an activator-support, an optional additional activatorand an optional cocatalyst. Such catalyst systems may be utilized in thepreparation of polymer resins such as polyolefins. In an embodiment, thepolymer resin comprises polyethylene, alternatively high densitypolyethylene. Polymer resins of the type described herein may be formedinto films that display improvements in barrier properties and as suchmay find particular utility in food packaging applications. Hereinaftersuch polymer resins are termed barrier-improved polymer (BIP)compositions. In an embodiment, a BIP composition is a polyethylenehomopolymer (e.g., a unimodal polyethylene homopolymer) having thephysical properties and characteristics described in more detail herein.

In an embodiment, a method of preparing a BIP composition comprisescontacting an alpha-olefin monomer with a catalyst system underconditions suitable for the formation of a polymer of the type describedherein. Any catalyst system compatible with and able to produce polymershaving the features disclosed herein may be employed. In an embodiment,the catalyst system comprises a transition-metal complex, anactivator-support, and an optional cocatalyst.

The terms “catalyst composition,” “catalyst mixture,” “catalyst system,”and the like, do not depend upon the actual product resulting from thecontact or reaction of the components of the mixtures, the nature of theactive catalytic site, or the fate of the cocatalyst, the transitionmetal complexes, any olefin monomer used to prepare a precontactedmixture, or the activator-support, after combining these components.Therefore, the terms “catalyst composition,” “catalyst mixture,”“catalyst system,” and the like, can include both heterogeneouscompositions and homogenous compositions.

With regard to the chemical groups defined herein, in one aspect, achemical “group” can be defined or described according to how that groupis formally derived from a reference or “parent” compound, for example,by the number of hydrogen atoms that are formally removed from theparent compound to generate the group, even if that group is notliterally synthesized in this manner. These groups can be utilized assubstituents or coordinated or bonded to metal atoms. By way of example,an “alkyl group” formally can be derived by removing one hydrogen atomfrom an alkane, an “alkenyl group” by removing one hydrogen atom from analkene, or an alkynyl group by removing one hydrogen atom from analkyne, while an “alkylene group” “alkenylene group” or “alkynylenegroup” formally can be derived by removing two hydrogen atoms from analkane, alkene, or alkyne, respectively. Moreover, a more general termcan be used to encompass a variety of groups that formally are derivedby removing any number (“one or more”) hydrogen atoms from a parentcompound, which in this example can be described as an “alkane group,”and which encompasses an “alkyl group,” an “alkylene group,” andmaterial have three or more hydrogen atoms, as necessary for thesituation, removed from an alkane. Throughout, the disclosure that asubstituent, ligand, or other chemical moiety may constitute aparticular “group” implies that the well-known rules of chemicalstructure and bonding are followed when that group is employed asdescribed. When describing a group as being “derived by,” “derivedfrom,” “formed by,” or “formed from,” such terms are used in a formalsense and are not intended to reflect any specific synthetic methods orprocedure, unless specified otherwise or the context requires otherwise.

The term “organyl group” is used herein in accordance with thedefinition specified by IUPAC: an organic substituent group, regardlessof functional type, having one free valence at a carbon atom. Similarly,an “organylene group” refers to an organic group, regardless offunctional type, derived by removing two hydrogen atoms from an organiccompound, either two hydrogen atoms from one carbon atom or one hydrogenatom from each of two different carbon atoms. An “organic group” refersto a generalized group formed by removing one or more hydrogen atomsfrom carbon atoms of an organic compound. Thus, an “organyl group,” an“organylene group,” and an “organic group” can contain organicfunctional group(s) and/or atom(s) other than carbon and hydrogen, thatis, an organic group that can comprise functional groups and/or atoms inaddition to carbon and hydrogen. For instance, non-limiting examples ofatoms other than carbon and hydrogen include halogens, oxygen, nitrogen,phosphorus, and the like. Non-limiting examples of functional groupsinclude ethers, aldehydes, ketones, esters, sulfides, amines, andphosphines, and so forth. In one aspect, the hydrogen atom(s) removed toform the “organyl group,” “organylene group,” or “organic group” may beattached to a carbon atom belonging to a functional group, for example,an acyl group (—C(O)R), a formyl group (—C(O)H), a carboxy group(—C(O)OH), a hydrocarboxycarbonyl group (—C(O)OR), a cyano group (—C≡N),a carbamoyl group (—C(O)NH₂), a N-hydrocarbylcarbamoyl group (—C(O)NHR),or N,N′-dihydrocarbylcarbamoyl group (—C(O)NR₂), among otherpossibilities. In another aspect, the hydrogen atom(s) removed to formthe “organyl group,” “organylene group,” or “organic group” may beattached to a carbon atom not belonging to, and remote from, afunctional group, for example, —CH₂C(O)CH₃, —CH₂NR₂, and the like. An“organyl group,” “organylene group,” or “organic group” may bealiphatic, inclusive of being cyclic or acyclic, or may be aromatic.“Organyl groups,” “organylene groups,” and “organic groups” alsoencompass heteroatom-containing rings, heteroatom-containing ringsystems, heteroaromatic rings, and heteroaromatic ring systems. “Organylgroups,” “organylene groups,” and “organic groups” may be linear orbranched unless otherwise specified. Finally, it is noted that the“organyl group,” “organylene group,” or “organic group” definitionsinclude “hydrocarbyl group,” “hydrocarbylene group,” “hydrocarbongroup,” respectively, and “alkyl group,” “alkylene group,” and “alkanegroup,” respectively, as members.

The term “hydrocarbyl group” is used herein in accordance with thedefinition specified by IUPAC: a univalent group formed by removing ahydrogen atom from a hydrocarbon (that is, a group containing onlycarbon and hydrogen). Non-limiting examples of hydrocarbyl groupsinclude ethyl, phenyl, tolyl, propenyl, and the like. Similarly, a“hydrocarbylene group” refers to a group formed by removing two hydrogenatoms from a hydrocarbon, either two hydrogen atoms from one carbon atomor one hydrogen atom from each of two different carbon atoms. Therefore,in accordance with the terminology used herein, a “hydrocarbon group”refers to a generalized group formed by removing one or more hydrogenatoms (as necessary for the particular group) from a hydrocarbon. A“hydrocarbyl group,” “hydrocarbylene group,” and “hydrocarbon group” canbe acyclic or cyclic groups, and/or may be linear or branched. A“hydrocarbyl group,” “hydrocarbylene group,” and “hydrocarbon group” caninclude rings, ring systems, aromatic rings, and aromatic ring systems,which contain only carbon and hydrogen. “Hydrocarbyl groups,”“hydrocarbylene groups,” and “hydrocarbon groups” include, by way ofexample, aryl, arylene, arene groups, alkyl, alkylene, alkane group,cycloalkyl, cycloalkylene, cycloalkane groups, aralkyl, aralkylene, andaralkane groups, respectively, among other groups as members.

The term “alkyl group” is used herein in accordance with the definitionspecified by IUPAC: a univalent group formed by removing a hydrogen atomfrom an alkane. Similarly, an “alkylene group” refers to a group formedby removing two hydrogen atoms from an alkane (either two hydrogen atomsfrom one carbon atom or one hydrogen atom from two different carbonatoms). An “alkane group” is a general term that refers to a groupformed by removing one or more hydrogen atoms (as necessary for theparticular group) from an alkane. An “alkyl group,” “alkylene group,”and “alkane group” can be acyclic or cyclic groups, and/or may be linearor branched unless otherwise specified. Primary, secondary, and tertiaryalkyl group are derived by removal of a hydrogen atom from a primary,secondary, tertiary carbon atom, respectively, of an alkane. The n-alkylgroup derived by removal of a hydrogen atom from a terminal carbon atomof a linear alkane. The groups RCH₂ (R≠H), R₂CH(R≠H), and R₃C(R≠H) areprimary, secondary, and tertiary alkyl groups, respectively.

In an embodiment, a catalyst system for preparation of a BIP comprisesthe contact product of a transition metal complex, an activator-supportand an optional cocatalyst. The transition metal complex may becharacterized by the general formulaM(Z)(R¹)(R²)L_(n)wherein M is a transition metal, alternatively chromium and Z, R¹, andR² are ligands coordinated to M, and L_(n) is a neutral donor groupwhere n is 0, 1 or 2. In another embodiment L_(n) can be tetrahydrofuran(THF), acetonitrile, pyridine, diethylether or bipyridine. In anembodiment, Z comprises a η³ to η⁵-cycloalkadienyl moiety. Nonlimitingexamples of η³ to η⁵-cycloalkadienyl moieties suitable for use in thisdisclosure include cyclopentadienyl ligands, indenyl ligands, fluorenylligands, and the like, including partially saturated or substitutedderivatives or analogs of any of these. Possible substituents on theseligands include hydrogen, therefore the description “substitutedderivatives thereof” in this disclosure comprises partially saturatedligands such as tetrahydroindenyl, tetrahydrofluorenyl,octahydrofluorenyl, partially saturated indenyl, partially saturatedfluorenyl, substituted partially saturated indenyl, substitutedpartially saturated fluorenyl, and the like. In an embodiment, Zcomprises a cyclopentadienyl moiety and the transition metal complex istermed a “half-sandwich complex.” The cyclopentadienyl moiety may becharacterized by the general structure;

In an embodiment, each R of the cyclopentadienyl moiety can bedifferent. In some embodiments, each R can be the same. In anembodiment, each R may be independently selected from the groupconsisting of hydrogen, an organyl group; or alternatively, a hydrogenand a hydrocarbyl group. In embodiments, each R can independently be Hor a C₁ to C₂₀ organyl group; alternatively, H or a C₁ to C₁₀ organylgroup; or alternatively, H or a C₁ to C₅ organyl group. In otherembodiments, each R can independently be H or a C₁ to C₂₀ hydrocarbylgroup; alternatively, H or a C₁ to C₁₀ hydrocarbyl group; oralternatively, H or a C₁ to C₅ hydrocarbyl group or alternatively H. Inan embodiment, R may be a C₁ to C₆₀ organylene group; alternatively, aC₁ to C₅₀ organylene group; alternatively, C₁ to C₄₀ organylene group;alternatively, a C₁ to C₃₀ organylene group; or alternatively, a C₁ toC₂₀ organylene group. In other embodiments, each R can independently bea C₁ to C₆₀ hydrocarbylene group; alternatively, a C₁ to C₅₀hydrocarbylene group; alternatively, a C₁ to C₄₀ hydrocarbylene group;alternatively, a C₁ to C₃₀ hydrocarbylene group; alternatively, a C₁ toC₂₀ hydrocarbylene group.

In some embodiments, each non-hydrogen R group may independently be analkyl group. In an embodiment, the alkyl group which may be utilized asa non-hydrogen R group may be a methyl group, an ethyl group, a propylgroup, a butyl group, a pentyl group, a hexyl group, a heptyl group, anoctyl group, a nonyl group, a decyl group, a undecyl group, a dodecylgroup, a tridecyl group, a tetradecyl group, a pentadecyl group, ahexadecyl group, a heptadecyl group, an octadecyl group, or a nonadecylgroup; or alternatively, a methyl group, an ethyl group, a propyl group,a butyl group, a pentyl group, a hexyl group, a heptyl group, an octylgroup, a nonyl group, or a decyl group. In some embodiments, the alkylgroup which may be utilized as a non-hydrogen R group may be a methylgroup, an ethyl group, a n-propyl group, an iso-propyl group, a n-butylgroup, an iso-butyl group, a sec-butyl group, a tert-butyl group, ann-pentyl group, an iso-pentyl group, a sec-pentyl group, or a neopentylgroup; alternatively, a methyl group, an ethyl group, an iso-propylgroup, a tert-butyl group, or a neopentyl group; alternatively, a methylgroup; alternatively, an ethyl group; alternatively, a n-propyl group;alternatively, an iso-propyl group; alternatively, a tert-butyl group;or alternatively, a neopentyl group.

In an embodiment, each R may independently be an alkylene groupalternatively, an alkenylene group. For example, each R mayindependently be a methylene group, an ethylene group, a propylenegroup, a butylene group, a pentylene group, a hexylene group, aheptylene group, an octylene group, a nonylene group, a decylene group,a undecylene group, a dodecylene group, a tridecylene group, atetradecylene group, a pentadecylene group, a hexadecylene group, aheptadecylene group, an octadecylene group, or a nonadecylene group; oralternatively, a methylene group, an ethylene group, a propylene group,a butylene group, a pentylene group, a hexylene group, a heptylenegroup, an octylene group, a nonylene group, a decylene group. In someembodiments, each R may independently be a methylene group, an ethylenegroup, a propylene group, a butylene group, or a pentylene group. Inother embodiments, each R may independently be a methylene group;alternatively, an ethylene group; alternatively, a propylene group;alternatively, a butylene group; alternatively, a pentylene group;alternatively, a hexylene group; alternatively, a heptylene group;alternatively, an octylene group; alternatively, a nonylene group;alternatively, a decylene group; alternatively, a undecylene group;alternatively, a dodecylene group; alternatively, a tridecylene group;alternatively, a tetradecylene group; alternatively, a pentadecylenegroup; alternatively, a hexadecylene group; alternatively, aheptadecylene group; alternatively, an octadecylene group; oralternatively, a nonadecylene group. In some embodiments, each R mayindependently be a eth-1,2-ylene group, a prop-1,3-ylene group, abut-1,4-ylene group, a but-2,3-ylene group, a pent-1,5-ylene group, a2,2-dimethylprop-1,3-ylene group, a hex-1,6-ylene group, or a2,3-dimethylbut-2,3-ylene group; alternatively, eth-1,2-ylene group, aprop-1,3-ylene group, a but-1,4-ylene group, a pent-1,5-ylene group, ora hex-1,6-ylene group; alternatively, a eth-1,2-ylene group;alternatively, a, prop-1,3-ylene group; alternatively, a but-1,4-ylenegroup; alternatively, a but-2,3-ylene group; alternatively, apent-1,5-ylene group; alternatively, a 2,2-dimethylprop-1,3-ylene group;alternatively, a hex-1,6-ylene group; or alternatively, a2,3-dimethylbut-2,3-ylene group.

In an embodiment, each R may independently be an ethenylene group, apropenylene group, a butenylene group, a pentenylene group, a hexenylenegroup, a heptenylene group, an octenylene group, a nonenylene group, adecenylene group, a undecenylene group, a dodecenylene group, atridecenylene group, a tetradecenylene group, a pentadecenylene group, ahexadecenylene group, a heptadecenylene group, an octadecenylene group,or a nonadecenylene group; or alternatively, an ethenylene group, apropenylene group, a butenylene group, a pentenylene group, a hexenylenegroup, a heptenylene group, an octenylene group, a nonenylene group, adecenylene group. In some embodiments, each R may independently be anethenylene group, a propenylene group, a butenylene group, or apentenylene group. In other embodiments, each R may independently be anethenylene group; alternatively, a propenylene group; alternatively, abutenylene group; alternatively, a pentenylene group; alternatively, ahexenylene group; alternatively, a heptenylene group; alternatively, anoctenylene group; alternatively, a nonenylene group; alternatively, adecenylene group; alternatively, a undecenylene group; alternatively, adodecenylene group; alternatively, a tridecenylene group; alternatively,a tetradecenylene group; alternatively, a pentadecenylene group;alternatively, a hexadecenylene group; alternatively, a heptadecenylenegroup; alternatively, an octadecenylene group; or alternatively, anonadecenylene group. Generally, the carbon-carbon double bond(s) of anyalkenylene group disclosed herein may be located at any position withinthe alkenylene group. In an embodiment, the alkenylene group contains aterminal carbon-carbon double bond.

In an embodiment, each R of the cyclopentadienyl group comprises analkyl group, alternatively a methyl group. In an embodiment, Z comprisesa pentamethylcyclopentadienyl group, hereinafter designated Cp*. Inanother embodiment, at least one R of the cyclopentadienyl groupcomprises an organylene group, alternatively a hydrocarbylene group. Inan embodiment the cyclopentadienyl group comprises one R groupcomprising —C(CH₃)₂CH₂CH₂CH═CH₂ and the remaining R groups comprisehydrogen, hereinafter designated Cp′. Alternatively the cyclopentadienylgroup comprises one R group comprising —CH₂CH₂CH═CH₂ and the remaining Rgroups comprise hydrogen and is hereinafter designated Cp″. Cp′ and Cp″may be prepared using any suitable methodology. For example, suitablepreparation methodologies are described in Brieger, et al., J. Org.Chem. 36 (1971) p 243; Bochmann, et al., in J. Organmet. Chem. 592(1999); Theopold, et al., J. Am. Chem. Soc. 111 (1989) p 9127; andFendrick, et al., in Inorg. Synth., 29 (1992) p 193, each of which areincorporated by reference herein in its entirety.

In an embodiment R¹ and R² can be different. In other embodiments, R¹and R² can be the same. In an embodiment, each of R¹ and R² may beindependently selected from the group consisting of a halide, an organylgroup, or, a hydrocarbyl group. In embodiments, each of R¹ and R² canindependently be a halide, a C₁ to C₂₀ organyl group; alternatively, aC₁ to C₁₀ organyl group; or alternatively, a C₁ to C₅ organyl group. Inother embodiments, each of R¹ and R² can independently be a halide, a C₁to C₂₀ hydrocarbyl group; alternatively, a C₁ to C₁₀ hydrocarbyl group;or alternatively a C₁ to C₅ hydrocarbyl group.

In some embodiments each of R¹ and R² may be independently selected fromthe group consisting of a halide, an alkyl group, a cycloalkyl group, asubstituted cycloalkyl group, an aryl group, a substituted aryl group, aheteroaryl group, and a substituted heteroaryl group. In otherembodiments, each of R¹ and R² may independently be a halide, an alkylgroup, a cycloalkyl group, a substituted cycloalkyl group, an arylgroup, or a substituted aryl group; alternatively, a halide;alternatively an alkyl group; alternatively, a cycloalkyl group or asubstituted cycloalkyl group; alternatively, an aryl group or asubstituted aryl group; or alternatively, a heteroaryl group or asubstitute heteroaryl group. In yet other embodiments, each of R¹ and R²may independently be a halide, alternatively, an alkyl group;alternatively, a cycloalkyl group; alternatively, a substitutedcycloalkyl group; alternatively, an aryl group; alternatively, asubstituted aryl group; alternatively, a heteroaryl group; oralternatively, a substituted heteroaryl group.

In an embodiment, each of R¹ and R² may independently be a fluoride,chloride, bromide, or iodide; alternatively, a fluoride or chloride;alternatively, a chloride. In some embodiments, at least two of R¹ andR² are a halide; alternatively, R¹ and/or R² are chloride.

In an embodiment, the alkyl group which may be utilized as a R¹ and/orR² group may be a methyl group, an ethyl group, a propyl group, a butylgroup, a pentyl group, a hexyl group, a heptyl group, an octyl group, anonyl group, a decyl group, a undecyl group, a dodecyl group, a tridecylgroup, a tetradecyl group, a pentadecyl group, a hexadecyl group, aheptadecyl group, an octadecyl group, or a nonadecyl group; oralternatively, a methyl group, an ethyl group, a propyl group, a butylgroup, a pentyl group, a hexyl group, a heptyl group, an octyl group, anonyl group, or a decyl group. In some embodiments, the alkyl groupwhich may be utilized as a R¹ and/or R² group may be a methyl group, anethyl group, a n-propyl group, an iso-propyl group, a n-butyl group, aniso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentylgroup, an iso-pentyl group, a sec-pentyl group, or a neopentyl group;alternatively, a methyl group, an ethyl group, an iso-propyl group, atert-butyl group, or a neopentyl group; alternatively, a methyl group;alternatively, an ethyl group; alternatively, a n-propyl group;alternatively, an iso-propyl group; alternatively, a tert-butyl group;or alternatively, a neopentyl group.

In an embodiment, the cycloalkyl group which may be utilized as a R¹and/or R² group may be a cyclobutyl group, a substituted cyclobutylgroup, a cyclopentyl group, a substituted cyclopentyl group, acyclohexyl group, a substituted cyclohexyl group, a cycloheptyl group, asubstituted cycloheptyl group, a cyclooctyl group, or a substitutedcyclooctyl group. In some embodiments, the cycloalkyl group which may beutilized as a R¹ and/or R² group may be a cyclopentyl group, asubstituted cyclopentyl group, a cyclohexyl group, or a substitutedcyclohexyl group. In other embodiments, the cycloalkyl group which maybe utilized as a R¹ and/or R² group may be a cyclobutyl group or asubstituted cyclobutyl group; alternatively, a cyclopentyl group or asubstituted cyclopentyl group; alternatively, a cyclohexyl group or asubstituted cyclohexyl group; alternatively, a cycloheptyl group or asubstituted cycloheptyl group; or alternatively, a cyclooctyl group, ora substituted cyclooctyl group. In further embodiments, the cycloalkylgroup which may be utilized as a R¹ and/or R² group may be a cyclopentylgroup; alternatively, a substituted cyclopentyl group; a cyclohexylgroup; or alternatively, a substituted cyclohexyl group. Substituentsfor the substituted cycloalkyl group are independently disclosed hereinand may be utilized without limitation to further describe thesubstituted cycloalkyl group which may be utilized as a R¹ and/or R²group.

In an aspect, the aryl group(s) which may be utilized as a R¹ and/or R²group may be a phenyl group, a substituted phenyl group, a naphthylgroup, or a substituted naphthyl group. In an embodiment, the arylgroup(s) which may be utilized as a R¹ and/or R² group may be a phenylgroup or a substituted phenyl group; alternatively, a naphthyl group ora substituted naphthyl group; alternatively, a phenyl group or anaphthyl group; or alternatively, a substituted phenyl group or asubstituted naphthyl group.

In an embodiment, the substituted phenyl group which may be utilized asa R¹ and/or R² group may be a 2-substituted phenyl group, a3-substituted phenyl group, a 4-substituted phenyl group, a2,4-disubstituted phenyl group, a 2,6-disubstituted phenyl group,3,5-disubstituted phenyl group, or a 2,4,6-trisubstituted phenyl group.In other embodiments, the substituted phenyl group which may be utilizedas a R¹ and/or R² group may be a 2-substituted phenyl group, a4-substituted phenyl group, a 2,4-disubstituted phenyl group, or a2,6-disubstituted phenyl group; alternatively, a 3-substituted phenylgroup or a 3,5-disubstituted phenyl group; alternatively, a2-substituted phenyl group or a 4-substituted phenyl group;alternatively, a 2,4-disubstituted phenyl group or a 2,6-disubstitutedphenyl group; alternatively, a 2-substituted phenyl group;alternatively, a 3-substituted phenyl group; alternatively, a4-substituted phenyl group; alternatively, a 2,4-disubstituted phenylgroup; alternatively, a 2,6-disubstituted phenyl group; alternatively,3,5-disubstituted phenyl group; or alternatively, a 2,4,6-trisubstitutedphenyl group.

In an embodiment, each non-hydrogen substituent(s) for the substitutedcycloalkyl group, substituted aryl group, or substituted heteroarylgroup which may be utilized as a R¹ and/or R² group may be independentlyselected from a halide, a C₁ to C₁₀ hydrocarbyl group, or a C₁ to C₁₀hydrocarboxy group; alternatively, a halide or a C₁ to C₁₀ hydrocarbylgroup; alternatively, a halide or a C₁ to C₁₀ hydrocarboxy group;alternatively, a C₁ to C₁₀ hydrocarbyl group or a C₁ to C₁₀ hydrocarboxygroup; alternatively, a halide; alternatively, a C₁ to C₁₀ hydrocarbylgroup; or alternatively, a C₁ to C₁₀ hydrocarboxy group. In someembodiments, each non-hydrogen substituent(s) for the substitutedcycloalkyl group, substituted aryl group, or substituted heteroarylgroup which may be utilized as a R¹ and/or R² group may be independentlyselected from a halide, a C₁ to C₅ hydrocarbyl group, or a C₁ to C₅hydrocarboxy group; alternatively, a halide or a C₁ to C₅ hydrocarbylgroup; alternatively, a halide or a C₁ to C₅ hydrocarboxy group;alternatively, a C₁ to C₅ hydrocarbyl group or a C₁ to C₅ hydrocarboxygroup; alternatively, a halide; alternatively, a C₁ to C₅ hydrocarbylgroup; or alternatively, a C₁ to C₅ hydrocarboxy group. Specificsubstituent halides, hydrocarbyl groups, and hydrocarboxy groups areindependently disclosed herein and may be utilized without limitation tofurther describe the substituents for the substituted cycloalkyl group,substituted aryl group, or substituted heteroaryl group which may beutilized as a R¹ and/or R² group.

In an embodiment, any halide substituent of a substituted cycloalkylgroup (general or specific), substituted aryl group (general orspecific), substituted heteroaryl (general or specific) may be afluoride, chloride, bromide, or iodide; alternatively, a fluoride orchloride. In some embodiments, any halide substituent of a substitutedcycloalkyl group (general or specific), substituted aryl group (generalor specific), substituted heteroaryl (general or specific) may be afluoride; alternatively, a chloride; alternatively, a bromide; oralternatively, an iodide.

In an embodiment, any hydrocarbyl substituent of a substitutedcycloalkyl group (general or specific), substituted aryl group (generalor specific), or substituted heteroaryl (general or specific) may be analkyl group, an aryl group, or an aralkyl group; alternatively, an alkylgroup; alternatively, an aryl group, or an aralkyl group. Generally, thealkyl, aryl, and aralkyl substituent groups may have the same number ofcarbon atoms as the hydrocarbyl substituent group disclosed herein. Inan embodiment, any alkyl substituent of a substituted cycloalkyl group(general or specific), substituted aryl group (general or specific),substituted heteroaryl (general or specific) may be a methyl group, anethyl group, an n-propyl group, an isopropyl group, an n-butyl group, asec-butyl group, an isobutyl group, a tert-butyl group, an n-pentylgroup, a 2-pentyl group, a 3-pentyl group, a 2-methyl-1-butyl group, atert-pentyl group, a 3-methyl-1-butyl group, a 3-methyl-2-butyl group,or a neo-pentyl group; alternatively, a methyl group, an ethyl group, anisopropyl group, a tert-butyl group, or a neo-pentyl group;alternatively, a methyl group; alternatively, an ethyl group;alternatively, an isopropyl group; alternatively, a tert-butyl group; oralternatively, a neo-pentyl group. In an embodiment, any arylsubstituent of a substituted cycloalkyl group (general or specific),substituted aryl group (general or specific), substituted heteroaryl(general or specific) may be phenyl group, a tolyl group, a xylyl group,or a 2,4,6-trimethylphenyl group; alternatively, a phenyl group;alternatively, a tolyl group, alternatively, a xylyl group; oralternatively, a 2,4,6-trimethylphenyl group. In an embodiment, anyaralkyl substituent of a substituted cycloalkyl group (general orspecific), substituted aryl group (general or specific), substitutedheteroaryl (general or specific) may be benzyl group.

In an embodiment, any hydrocarboxy substituent of a substitutedcycloalkyl group (general or specific), substituted aryl group (generalor specific), substituted heteroaryl (general or specific) may be analkoxy group, an aryloxy group, or and aralkoxy group; alternatively, analkoxy group; alternatively, an aryloxy group, or an aralkoxy group.Generally, the alkoxy, aryloxy, and aralkoxy substituent groups may havethe same number of carbon atoms as the hydrocarboxy substituent groupdisclosed herein. In an embodiment, any alkoxy substituent of asubstituted cycloalkyl group (general or specific), substituted arylgroup (general or specific), substituted heteroaryl (general orspecific) may be a methoxy group, an ethoxy group, an n-propoxy group,an isopropoxy group, an n-butoxy group, a sec-butoxy group, an isobutoxygroup, a tert-butoxy group, an n-pentoxy group, a 2-pentoxy group, a3-pentoxy group, a 2-methyl-1-butoxy group, a tert-pentoxy group, a3-methyl-1-butoxy group, a 3-methyl-2-butoxy group, or a neo-pentoxygroup; alternatively, a methoxy group, an ethoxy group, an isopropoxygroup, a tert-butoxy group, or a neo-pentoxy group; alternatively, amethoxy group; alternatively, an ethoxy, group; alternatively, anisopropoxy group; alternatively, a tert-butoxy group; or alternatively,a neo-pentoxy group. In an embodiment, any aroxy substituent of asubstituted cycloalkyl group (general or specific), substituted arylgroup (general or specific), substituted heteroaryl (general orspecific) may be phenoxy group, a toloxy group, a xyloxy group, or a2,4,6-trimethylphenoxy group; alternatively, a phenoxy group;alternatively, a toloxy group, alternatively, a xyloxy group; oralternatively, a 2,4,6-trimethylphenoxy group. In an embodiment, anyaralkoxy substituent of a substituted cycloalkyl group (general orspecific), substituted aryl group (general or specific), substitutedheteroaryl (general or specific) may be benzoxy group.

In an embodiment, a transition metal complex suitable for use in thisdisclosure comprises Cp*Cr(CH₃)₂(py) as represented by Formula I.

In an embodiment, a transition metal complex suitable for use in thisdisclosure comprises Cp′Cr(Cl)₂(THF) as represented by Formula II.

In an embodiment, a transition metal complex suitable for use in thisdisclosure comprises Cp″Cr(Cl)₂(THF) as represented by Formula III.

Alternatively the catalyst system comprises more than one of thetransition metal complexes.

A catalyst system for preparation of a BIP may further comprise anactivator-support. The present disclosure encompasses various catalystcompositions containing an activator, which can be an activator-support.In one aspect, the activator-support comprises a chemically-treatedsolid oxide. Alternatively, the activator-support can comprise a claymineral, a pillared clay, an exfoliated clay, an exfoliated clay gelledinto another oxide matrix, a layered silicate mineral, a non-layeredsilicate mineral, a layered aluminosilicate mineral, a non-layeredaluminosilicate mineral, or any combination thereof.

Generally, chemically-treated solid oxides exhibit enhanced acidity ascompared to the corresponding untreated solid oxide compound. Thechemically-treated solid oxide also functions as a catalyst activator ascompared to the corresponding untreated solid oxide. While thechemically-treated solid oxide activates the metallocene(s) in theabsence of co-catalysts, it is not necessary to eliminate co-catalystsfrom the catalyst composition. The activation function of theactivator-support is evident in the enhanced activity of catalystcomposition as a whole, as compared to a catalyst composition containingthe corresponding untreated solid oxide. However, it is believed thatthe chemically-treated solid oxide can function as an activator, even inthe absence of an organoaluminum compound, aluminoxanes, organoboron ororganoborate compounds, ionizing ionic compounds, and the like.

The chemically-treated solid oxide can comprise a solid oxide treatedwith an electron-withdrawing anion. While not intending to be bound bythe following statement, it is believed that treatment of the solidoxide with an electron-withdrawing component augments or enhances theacidity of the oxide. Thus, either the activator-support exhibits Lewisor Brønsted acidity that is typically greater than the Lewis or Brønstedacid strength of the untreated solid oxide, or the activator-support hasa greater number of acid sites than the untreated solid oxide, or both.One method to quantify the acidity of the chemically-treated anduntreated solid oxide materials is by comparing the polymerizationactivities of the treated and untreated oxides under acid catalyzedreactions.

Chemically-treated solid oxides of this disclosure are formed generallyfrom an inorganic solid oxide that exhibits Lewis acidic or Brønstedacidic behavior and has a relatively high porosity. The solid oxide ischemically-treated with an electron-withdrawing component, typically anelectron-withdrawing anion, to form an activator-support.

According to one aspect of the present disclosure, the solid oxide usedto prepare the chemically-treated solid oxide has a pore volume greaterthan about 0.1 cc/g. According to another aspect of the presentdisclosure, the solid oxide has a pore volume greater than about 0.5cc/g. According to yet another aspect of the present disclosure, thesolid oxide has a pore volume greater than about 1.0 cc/g.

In another aspect, the solid oxide has a surface area of from about 100to about 1000 m²/g. In yet another aspect, the solid oxide has a surfacearea of from about 200 to about 800 m²/g. In still another aspect of thepresent disclosure, the solid oxide has a surface area of from about 250to about 600 m²/g.

The chemically-treated solid oxide can comprise a solid inorganic oxidecomprising oxygen and one or more elements selected from Group 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, or 15 of the periodic table, orcomprising oxygen and one or more elements selected from the lanthanideor actinide elements (See: Hawley's Condensed Chemical Dictionary,11^(th) Ed., John Wiley & Sons, 1995; Cotton, F. A., Wilkinson, G.,Murillo, C. A., and Bochmann, M., Advanced Inorganic Chemistry, 6^(th)Ed., Wiley-Interscience, 1999). For example, the inorganic oxide cancomprise oxygen and an element, or elements, selected from Al, B, Be,Bi, Cd, Co, Cr, Cu, Fe, Ga, La, Mn, Mo, Ni, Sb, Si, Sn, Sr, Th, Ti, V,W, P, Y, Zn, and Zr.

Suitable examples of solid oxide materials or compounds that can be usedto form the chemically-treated solid oxide include, but are not limitedto, Al₂O₃, B₂O₃, BeO, Bi₂O₃, CdO, CO₃O₄, Cr₂O₃, CuO, Fe₂O₃, Ga₂O₃,La₂O₃, Mn₂O₃, MoO₃, NiO, P₂O₅, Sb₂O₅, SiO₂, SnO₂, SrO, ThO₂, TiO₂, V₂O₅,WO₃, Y₂O₃, ZnO, ZrO₂, and the like, including mixed oxides thereof, andcombinations thereof. For example, the solid oxide can comprise silica,alumina, silica-alumina, silica-coated alumina, aluminum phosphate,aluminophosphate, heteropolytungstate, titania, zirconia, magnesia,boria, zinc oxide, mixed oxides thereof, or any combination thereof.

The solid oxide of this disclosure encompasses oxide materials such asalumina, “mixed oxide” compounds thereof such as silica-alumina, andcombinations and mixtures thereof. The mixed oxide compounds such assilica-alumina can be single or multiple chemical phases with more thanone metal combined with oxygen to form a solid oxide compound. Examplesof mixed oxides that can be used in the activator-support of the presentdisclosure include, but are not limited to, silica-alumina,silica-titania, silica-zirconia, zeolites, various clay minerals,alumina-titania, alumina-zirconia, zinc-aluminate, alumina-boria,silica-boria, aluminophosphate-silica, titania-zirconia, and the like.The solid oxide of this disclosure also encompasses oxide materials suchas silica-coated alumina, as described in U.S. Patent Publication No.2010-0076167, the disclosure of which is incorporated herein byreference in its entirety.

The electron-withdrawing component used to treat the solid oxide can beany component that increases the Lewis or Brønsted acidity of the solidoxide upon treatment (as compared to the solid oxide that is not treatedwith at least one electron-withdrawing anion). According to one aspectof the present disclosure, the electron-withdrawing component is anelectron-withdrawing anion derived from a salt, an acid, or othercompound, such as a volatile organic compound, that serves as a sourceor precursor for that anion. Examples of electron-withdrawing anionsinclude, but are not limited to, sulfate, bisulfate, fluoride, chloride,bromide, iodide, fluorosulfate, fluoroborate, phosphate,fluorophosphate, trifluoroacetate, triflate, fluorozirconate,fluorotitanate, phospho-tungstate, and the like, including mixtures andcombinations thereof. In addition, other ionic or non-ionic compoundsthat serve as sources for these electron-withdrawing anions also can beemployed in the present disclosure. It is contemplated that theelectron-withdrawing anion can be, or can comprise, fluoride, chloride,bromide, phosphate, triflate, bisulfate, or sulfate, and the like, orany combination thereof, in some aspects of this disclosure. In otheraspects, the electron-withdrawing anion can comprise sulfate, bisulfate,fluoride, chloride, bromide, iodide, fluorosulfate, fluoroborate,phosphate, fluorophosphate, trifluoroacetate, triflate, fluorozirconate,fluorotitanate, and the like, or any combination thereof.

Thus, for example, the activator-support (e.g., chemically-treated solidoxide) used in the catalyst compositions of the present disclosure(e.g., BIP) can be, or can comprise, fluorided alumina, chloridedalumina, bromided alumina, sulfated alumina, fluorided silica-alumina,chlorided silica-alumina, bromided silica-alumina, sulfatedsilica-alumina, fluorided silica-zirconia, chlorided silica-zirconia,bromided silica-zirconia, sulfated silica-zirconia, fluoridedsilica-titania, fluorided silica-coated alumina, sulfated silica-coatedalumina, phosphated silica-coated alumina, and the like, or combinationsthereof. In one aspect, the activator-support can be, or can comprise,fluorided alumina, sulfated alumina, fluorided silica-alumina, sulfatedsilica-alumina, fluorided silica-coated alumina, sulfated silica-coatedalumina, phosphated silica-coated alumina, and the like, or anycombination thereof. In another aspect, the activator-support comprisesfluorided alumina; alternatively, comprises chlorided alumina;alternatively, comprises sulfated alumina; alternatively, comprisesfluorided silica-alumina; alternatively, comprises sulfatedsilica-alumina; alternatively, comprises fluorided silica-zirconia;alternatively, comprises chlorided silica-zirconia; or alternatively,comprises fluorided silica-coated alumina.

When the electron-withdrawing component comprises a salt of anelectron-withdrawing anion, the counterion or cation of that salt can beselected from any cation that allows the salt to revert or decomposeback to the acid during calcining. Factors that dictate the suitabilityof the particular salt to serve as a source for the electron-withdrawinganion include, but are not limited to, the solubility of the salt in thedesired solvent, the lack of adverse reactivity of the cation,ion-pairing effects between the cation and anion, hygroscopic propertiesimparted to the salt by the cation, and the like, and thermal stabilityof the anion. Examples of suitable cations in the salt of theelectron-withdrawing anion include, but are not limited to, ammonium,trialkyl ammonium, tetraalkyl ammonium, tetraalkyl phosphonium, H⁺,[H(OEt₂)₂]⁺, and the like.

Further, combinations of one or more different electron-withdrawinganions, in varying proportions, can be used to tailor the specificacidity of the activator-support to the desired level. Combinations ofelectron-withdrawing components can be contacted with the oxide materialsimultaneously or individually, and in any order that affords thedesired chemically-treated solid oxide acidity. For example, one aspectof this disclosure is employing two or more electron-withdrawing anionsource compounds in two or more separate contacting steps.

Thus, one example of such a process by which a chemically-treated solidoxide is prepared is as follows: a selected solid oxide, or combinationof solid oxides, is contacted with a first electron-withdrawing anionsource compound to form a first mixture; this first mixture is calcinedand then contacted with a second electron-withdrawing anion sourcecompound to form a second mixture; the second mixture is then calcinedto form a treated solid oxide. In such a process, the first and secondelectron-withdrawing anion source compounds can be either the same ordifferent compounds.

According to another aspect of the present disclosure, thechemically-treated solid oxide comprises a solid inorganic oxidematerial, a mixed oxide material, or a combination of inorganic oxidematerials, that is chemically-treated with an electron-withdrawingcomponent, and optionally treated with a metal source, including metalsalts, metal ions, or other metal-containing compounds. Nonlimitingexamples of the metal or metal ion include zinc, nickel, vanadium,titanium, silver, copper, gallium, tin, tungsten, molybdenum, zirconium,and the like, or combinations thereof. Examples of chemically-treatedsolid oxides that contain a metal or metal ion include, but are notlimited to, chlorided zinc-impregnated alumina, fluoridedtitanium-impregnated alumina, fluorided zinc-impregnated alumina,chlorided zinc-impregnated silica-alumina, fluorided zinc-impregnatedsilica-alumina, sulfated zinc-impregnated alumina, chlorided zincaluminate, fluorided zinc aluminate, sulfated zinc aluminate,silica-coated alumina treated with hexafluorotitanic acid, silica-coatedalumina treated with zinc and then fluorided, and the like, or anycombination thereof.

Any method of impregnating the solid oxide material with a metal can beused. The method by which the oxide is contacted with a metal source,typically a salt or metal-containing compound, can include, but is notlimited to, gelling, co-gelling, impregnation of one compound ontoanother, and the like. If desired, the metal-containing compound isadded to or impregnated into the solid oxide in solution form, andsubsequently converted into the supported metal upon calcining.Accordingly, the solid inorganic oxide can further comprise a metalselected from zinc, titanium, nickel, vanadium, silver, copper, gallium,tin, tungsten, molybdenum, and the like, or combinations of thesemetals. For example, zinc is often used to impregnate the solid oxidebecause it can provide improved catalyst activity at a low cost.

The solid oxide can be treated with metal salts or metal-containingcompounds before, after, or at the same time that the solid oxide istreated with the electron-withdrawing anion. Following any contactingmethod, the contacted mixture of solid compound, electron-withdrawinganion, and the metal ion is typically calcined. Alternatively, a solidoxide material, an electron-withdrawing anion source, and the metal saltor metal-containing compound are contacted and calcined simultaneously.

Various processes are used to form the chemically-treated solid oxideuseful in the present disclosure. The chemically-treated solid oxide cancomprise the contact product of one or more solid oxides with one ormore electron-withdrawing anion sources. It is not required that thesolid oxide be calcined prior to contacting the electron-withdrawinganion source. The contact product typically is calcined either during orafter the solid oxide is contacted with the electron-withdrawing anionsource. The solid oxide can be calcined or uncalcined. Various processesto prepare solid oxide activator-supports that can be employed in thisdisclosure have been reported. For example, such methods are describedin U.S. Pat. Nos. 6,107,230; 6,165,929; 6,294,494; 6,300,271; 6,316,553;6,355,594; 6,376,415; 6,388,017; 6,391,816; 6,395,666; 6,524,987;6,548,441; 6,548,442; 6,576,583; 6,613,712; 6,632,894; 6,667,274;6,750,302; 7,226,886; 7,294,599; 7,601,655; and 7,732,542 thedisclosures of which are incorporated herein by reference in their,entirety.

According to one aspect of the present disclosure, the solid oxidematerial is chemically-treated by contacting it with anelectron-withdrawing component, typically an electron-withdrawing anionsource. Further, the solid oxide material optionally is chemicallytreated with a metal ion, and then calcined to form a metal-containingor metal-impregnated chemically-treated solid oxide. According toanother aspect of the present disclosure, the solid oxide material andelectron-withdrawing anion source are contacted and calcinedsimultaneously.

The method by which the oxide is contacted with the electron-withdrawingcomponent, typically a salt or an acid of an electron-withdrawing anion,can include, but is not limited to, gelling, co-gelling, impregnation ofone compound onto another, and the like. Thus, following any contactingmethod, the contacted mixture of the solid oxide, electron-withdrawinganion, and optional metal ion, is calcined.

The solid oxide activator-support (i.e., chemically-treated solid oxide)thus can be produced by a process comprising:

1) contacting a solid oxide (or solid oxides) with anelectron-withdrawing anion source compound (or compounds) to form afirst mixture; and

2) calcining the first mixture to form the solid oxideactivator-support.

According to another aspect of the present disclosure, the solid oxideactivator-support (chemically-treated solid oxide) is produced by aprocess comprising:

1) contacting a solid oxide (or solid oxides) with a firstelectron-withdrawing anion source compound to form a first mixture;

2) calcining the first mixture to produce a calcined first mixture;

3) contacting the calcined first mixture with a secondelectron-withdrawing anion source compound to form a second mixture; and

4) calcining the second mixture to form the solid oxideactivator-support.

According to yet another aspect of the present disclosure, thechemically-treated solid oxide is produced or formed by contacting thesolid oxide with the electron-withdrawing anion source compound, wherethe solid oxide compound is calcined before, during, or after contactingthe electron-withdrawing anion source, and where there is a substantialabsence of aluminoxanes, organoboron or organoborate compounds, andionizing ionic compounds.

Calcining of the treated solid oxide generally is conducted in anambient atmosphere, typically in a dry ambient atmosphere, at atemperature from about 200° C. to about 900° C., and for a time of about1 minute to about 100 hours. Calcining can be conducted at a temperatureof from about 300° C. to about 800° C., or alternatively, at atemperature of from about 400° C. to about 700° C. Calcining can beconducted for about 30 minutes to about 50 hours, or for about 1 hour toabout 15 hours. Thus, for example, calcining can be carried out forabout 1 to about 10 hours at a temperature of from about 350° C. toabout 550° C. Any suitable ambient atmosphere can be employed duringcalcining. Generally, calcining is conducted in an oxidizing atmosphere,such as air. Alternatively, an inert atmosphere, such as nitrogen orargon, or a reducing atmosphere, such as hydrogen or carbon monoxide,can be used.

According to one aspect of the present disclosure, the solid oxidematerial is treated with a source of halide ion, sulfate ion, or acombination of anions, optionally treated with a metal ion, and thencalcined to provide the chemically-treated solid oxide in the form of aparticulate solid. For example, the solid oxide material can be treatedwith a source of sulfate (termed a “sulfating agent”), a source ofchloride ion (termed a “chloriding agent”), a source of fluoride ion(termed a “fluoriding agent”), or a combination thereof, and calcined toprovide the solid oxide activator. Useful acidic activator-supportsinclude, but are not limited to, bromided alumina, chlorided alumina,fluorided alumina, sulfated alumina, bromided silica-alumina, chloridedsilica-alumina, fluorided silica-alumina, sulfated silica-alumina,bromided silica-zirconia, chlorided silica-zirconia, fluoridedsilica-zirconia, sulfated silica-zirconia, fluorided silica-titania,alumina treated with hexafluorotitanic acid, silica-coated aluminatreated with hexafluorotitanic acid, silica-alumina treated withhexafluorozirconic acid, silica-alumina treated with trifluoroaceticacid, fluorided boria-alumina, silica treated with tetrafluoroboricacid, alumina treated with tetrafluoroboric acid, alumina treated withhexafluorophosphoric acid, a pillared clay, such as a pillaredmontmorillonite, optionally treated with fluoride, chloride, or sulfate;phosphated alumina or other aluminophosphates optionally treated withsulfate, fluoride, or chloride; or any combination of the above.Further, any of these activator-supports optionally can be treated witha metal ion.

The chemically-treated solid oxide can comprise a fluorided solid oxidein the form of a particulate solid. The fluorided solid oxide can beformed by contacting a solid oxide with a fluoriding agent. The fluorideion can be added to the oxide by forming a slurry of the oxide in asuitable solvent such as alcohol or water including, but not limited to,the one to three carbon alcohols because of their volatility and lowsurface tension. Examples of suitable fluoriding agents include, but arenot limited to, hydrofluoric acid (HF), ammonium fluoride (NH₄F),ammonium bifluoride (NH₄HF₂), ammonium tetrafluoroborate (NH₄BF₄),ammonium silicofluoride (hexafluorosilicate) ((NH₄)₂SiF₆), ammoniumhexafluorophosphate (NH₄ PF₆), hexafluorotitanic acid (H₂TiF₆), ammoniumhexafluorotitanic acid ((NH₄)₂TiF₆), hexafluorozirconic acid (H₂ZrF₆),AlF₃, NH₄AlF₄, analogs thereof, and combinations thereof. Triflic acidand ammonium triflate also can be employed. For example, ammoniumbifluoride (NH₄HF₂) can be used as the fluoriding agent, due to its easeof use and availability.

If desired, the solid oxide is treated with a fluoriding agent duringthe calcining step. Any fluoriding agent capable of thoroughlycontacting the solid oxide during the calcining step can be used. Forexample, in addition to those fluoriding agents described previously,volatile organic fluoriding agents can be used. Examples of volatileorganic fluoriding agents useful in this aspect of the disclosureinclude, but are not limited to, freons, perfluorohexane,perfluorobenzene, fluoromethane, trifluoroethanol, and the like, andcombinations thereof. Calcining temperatures generally must be highenough to decompose the compound and release fluoride. Gaseous hydrogenfluoride (HF) or fluorine (F₂) itself also can be used with the solidoxide if fluorided while calcining. Silicon tetrafluoride (SiF₄) andcompounds containing tetrafluoroborate (BF₄ ⁻) also can be employed. Oneconvenient method of contacting the solid oxide with the fluoridingagent is to vaporize a fluoriding agent into a gas stream used tofluidize the solid oxide during calcination.

Similarly, in another aspect of this disclosure, the chemically-treatedsolid oxide comprises a chlorided solid oxide in the form of aparticulate solid. The chlorided solid oxide is formed by contacting asolid oxide with a chloriding agent. The chloride ion can be added tothe oxide by forming a slurry of the oxide in a suitable solvent. Thesolid oxide can be treated with a chloriding agent during the calciningstep. Any chloriding agent capable of serving as a source of chlorideand thoroughly contacting the oxide during the calcining step can beused, such as SiCl₄, SiMe₂Cl₂, TiCl₄, BCl₃, and the like, includingmixtures thereof. Volatile organic chloriding agents can be used.Examples of suitable volatile organic chloriding agents include, but arenot limited to, certain freons, perchlorobenzene, chloromethane,dichloromethane, chloroform, carbon tetrachloride, trichloroethanol, andthe like, or any combination thereof. Gaseous hydrogen chloride orchlorine itself also can be used with the solid oxide during calcining.One convenient method of contacting the oxide with the chloriding agentis to vaporize a chloriding agent into a gas stream used to fluidize thesolid oxide during calcination.

The amount of fluoride or chloride ion present before calcining thesolid oxide generally is from about 1 to about 50% by weight, where theweight percent is based on the weight of the solid oxide, for example,silica-alumina, before calcining. According to another aspect of thisdisclosure, the amount of fluoride or chloride ion present beforecalcining the solid oxide is from about 1 to about 25% by weight, andaccording to another aspect of this disclosure, from about 2 to about20% by weight. According to yet another aspect of this disclosure, theamount of fluoride or chloride ion present before calcining the solidoxide is from about 4 to about 10% by weight. Once impregnated withhalide, the halided oxide can be dried by any suitable method including,but not limited to, suction filtration followed by evaporation, dryingunder vacuum, spray drying, and the like, although it is also possibleto initiate the calcining step immediately without drying theimpregnated solid oxide.

The silica-alumina used to prepare the treated silica-alumina typicallyhas a pore volume greater than about 0.5 cc/g. According to one aspectof the present disclosure, the pore volume is greater than about 0.8cc/g, and according to another aspect of the present disclosure, greaterthan about 1.0 cc/g. Further, the silica-alumina generally has a surfacearea greater than about 100 m²/g. According to another aspect of thisdisclosure, the surface area is greater than about 250 m²/g. Yet, inanother aspect, the surface area is greater than about 350 m²/g.

The silica-alumina utilized in the present disclosure typically has analumina content from about 5 to about 95% by weight. According to oneaspect of this disclosure, the alumina content of the silica-alumina isfrom about 5 to about 50%, or from about 8% to about 30%, alumina byweight. In another aspect, high alumina content silica-alumina compoundscan employed, in which the alumina content of these silica-aluminacompounds typically ranges from about 60% to about 90%, or from about65% to about 80%, alumina by weight. According to yet another aspect ofthis disclosure, the solid oxide component comprises alumina withoutsilica, and according to another aspect of this disclosure, the solidoxide component comprises silica without alumina.

The sulfated solid oxide comprises sulfate and a solid oxide component,such as alumina or silica-alumina, in the form of a particulate solid.Optionally, the sulfated oxide is treated further with a metal ion suchthat the calcined sulfated oxide comprises a metal. According to oneaspect of the present disclosure, the sulfated solid oxide comprisessulfate and alumina. In some instances, the sulfated alumina is formedby a process wherein the alumina is treated with a sulfate source, forexample, sulfuric acid or a sulfate salt such as ammonium sulfate. Thisprocess is generally performed by forming a slurry of the alumina in asuitable solvent, such as alcohol or water, in which the desiredconcentration of the sulfating agent has been added. Suitable organicsolvents include, but are not limited to, the one to three carbonalcohols because of their volatility and low surface tension.

According to one aspect of this disclosure, the amount of sulfate ionpresent before calcining is from about 0.5 to about 100 parts by weightsulfate ion to about 100 parts by weight solid oxide. According toanother aspect of this disclosure, the amount of sulfate ion presentbefore calcining is from about 1 to about 50 parts by weight sulfate ionto about 100 parts by weight solid oxide, and according to still anotheraspect of this disclosure, from about 5 to about 30 parts by weightsulfate ion to about 100 parts by weight solid oxide. These weightratios are based on the weight of the solid oxide before calcining. Onceimpregnated with sulfate, the sulfated oxide can be dried by anysuitable method including, but not limited to, suction filtrationfollowed by evaporation, drying under vacuum, spray drying, and thelike, although it is also possible to initiate the calcining stepimmediately.

According to another aspect of the present disclosure, theactivator-support used in preparing the catalyst compositions of thisdisclosure comprises an ion-exchangeable activator-support, includingbut not limited to silicate and aluminosilicate compounds or minerals,either with layered or non-layered structures, and combinations thereof.In another aspect of this disclosure, ion-exchangeable, layeredaluminosilicates such as pillared clays are used as activator-supports.When the acidic activator-support comprises an ion-exchangeableactivator-support, it can optionally be treated with at least oneelectron-withdrawing anion such as those disclosed herein, thoughtypically the ion-exchangeable activator-support is not treated with anelectron-withdrawing anion.

According to another aspect of the present disclosure, theactivator-support of this disclosure comprises clay minerals havingexchangeable cations and layers capable of expanding. Typical claymineral activator-supports include, but are not limited to,ion-exchangeable, layered aluminosilicates such as pillared clays.Although the term “support” is used, it is not meant to be construed asan inert component of the catalyst composition, but rather is to beconsidered an active part of the catalyst composition, because of itsintimate association with the metallocene component.

According to another aspect of the present disclosure, the claymaterials of this disclosure encompass materials either in their naturalstate or that have been treated with various ions by wetting, ionexchange, or pillaring. Typically, the clay material activator-supportof this disclosure comprises clays that have been ion exchanged withlarge cations, including polynuclear, highly, charged metal complexcations. However, the clay material activator-supports of thisdisclosure also encompass clays that have been ion exchanged with simplesalts, including, but not limited to, salts of Al(III), Fe(II), Fe(III),and Zn(II) with ligands such as halide, acetate, sulfate, nitrate, ornitrite.

According to another aspect of the present disclosure, theactivator-support comprises a pillared clay. The term “pillared clay” isused to refer to clay materials that have been ion exchanged with large,typically polynuclear, highly charged metal complex cations. Examples ofsuch ions include, but are not limited to, Keggin ions which can havecharges such as 7+, various polyoxometallates, and other large ions.Thus, the term pillaring refers to a simple exchange reaction in whichthe exchangeable cations of a clay material are replaced with large,highly charged ions, such as Keggin ions. These polymeric cations arethen immobilized within the interlayers of the clay and when calcinedare converted to metal oxide “pillars,” effectively supporting the claylayers as column-like structures. Thus, once the clay is dried andcalcined to produce the supporting pillars between clay layers, theexpanded lattice structure is maintained and the porosity is enhanced.The resulting pores can vary in shape and size as a function of thepillaring material and the parent clay material used. Examples ofpillaring and pillared clays are found in: T. J. Pinnavaia, Science 220(4595), 365-371 (1983); J. M. Thomas, Intercalation Chemistry, (S.Whittington and A. Jacobson, eds.) Ch. 3, pp. 55-99, Academic Press,Inc., (1972); U.S. Pat. Nos. 4,452,910; 5,376,611; and 4,060,480; thedisclosures of which are incorporated herein by reference in theirentirety.

The pillaring process utilizes clay minerals having exchangeable cationsand layers capable of expanding. Any pillared clay that can enhance thepolymerization of olefins in the catalyst composition of the presentdisclosure can be used. Therefore, suitable clay minerals for pillaringinclude, but are not limited to, allophanes; smectites, bothdioctahedral (Al) and tri-octahedral (Mg) and derivatives thereof suchas montmorillonites (bentonites), nontronites, hectorites, or LAPONITE®(manufactured by Rockwood Additives Limited); halloysites; vermiculites;micas; fluoromicas; chlorites; mixed-layer clays; the fibrous claysincluding but not limited to sepiolites, attapulgites, andpalygorskites; a serpentine clay; illite; LAPONITE® (manufactured byRockwood Additives Limited); saponite; and any combination thereof. Inone aspect, the pillared clay activator-support comprises bentonite ormontmorillonite. The principal component of bentonite ismontmorillonite.

The pillared clay can be pretreated if desired. For example, a pillaredbentonite is pretreated by drying at about 300° C. under an inertatmosphere, typically dry nitrogen, for about 3 hours, before beingadded to the polymerization reactor. Although an exemplary pretreatmentis described herein, it should be understood that the preheating can becarried out at many other temperatures and times, including anycombination of temperature and time steps, all of which are encompassedby this disclosure.

The activator-support used to prepare the catalyst compositions of thepresent disclosure can be combined with other inorganic supportmaterials, including, but not limited to, zeolites, inorganic oxides,phosphated inorganic oxides, and the like. In one aspect, typicalsupport materials that are used include, but are not limited to, silica,silica-alumina, alumina, titania, zirconia, magnesia, boria, thoria,aluminophosphate, aluminum phosphate, silica-titania, coprecipitatedsilica/titania, mixtures thereof, or any combination thereof.

According to another aspect of the present disclosure, one or more ofthe metallocene compounds can be precontacted with an olefin monomer andan organoaluminum compound for a first period of time prior tocontacting this mixture with the activator-support. Once theprecontacted mixture of the metallocene compound(s), olefin monomer, andorganoaluminum compound is contacted with the activator-support, thecomposition further comprising the activator-support is termed a“postcontacted” mixture. The postcontacted mixture can be allowed toremain in further contact for a second period of time prior to beingcharged into the reactor in which the polymerization process will becarried out.

According to yet another aspect of the present disclosure, one or moreof the metallocene compounds can be precontacted with an olefin monomerand an activator-support for a first period of time prior to contactingthis mixture with the organoaluminum compound. Once the precontactedmixture of the metallocene compound(s), olefin monomer, andactivator-support is contacted with the organoaluminum compound, thecomposition further comprising the organoaluminum is termed a“postcontacted” mixture. The postcontacted mixture can be allowed toremain in further contact for a second period of time prior to beingintroduced into the polymerization reactor.

In an embodiment, the activator or activator-support is present in thecatalyst system (i.e., BIP) in an amount of from about 1 wt. % to about90 wt. %, alternatively from about 5 wt. % to about 90 wt. %,alternatively from about 10 wt. % to about 90 wt. % based on the totalweight of catalyst. In an embodiment, the weight ratio of metallocenecompound(s) to activator-support is in a range from about 1:1 to about1:1,000,000. If more than one activator-support is employed, this ratiois based on the total weight of the activator-support. In anotherembodiment, this weight ratio is in a range from about 1:5 to about1:100,000, or from about 1:10 to about 1:10,000. Yet, in another aspect,the weight ratio of the metallocene compound(s) to the activator-supportis in a range from about 1:20 to about 1:1000.

In an embodiment, a catalyst system of the type disclosed hereincomprises an activator-support (or activator) which comprises achemically-treated solid oxide (e.g., sulfated alumina). The catalystsystem comprising a chemically-treated solid oxide may function asdescribed herein in the absence of any additional activators. In anembodiment, a catalyst system of the type described herein comprises achemically-treated solid oxide as an activator and excludes additionalactivators. In an alternative embodiment, a catalyst system of the typedescribed herein comprises a chemically treated solid oxide as anactivator and at least one additional activator.

In an embodiment, the additional activator comprises an aluminoxanecompound. As used herein, the term “aluminoxane” refers to aluminoxanecompounds, compositions, mixtures, or discrete species, regardless ofhow such aluminoxanes are prepared, formed or otherwise provided.Aluminoxanes are also referred to as poly(hydrocarbyl aluminum oxides)or organoaluminoxanes.

The aluminoxane compound of this disclosure can be an oligomericaluminum compound comprising linear structures, cyclic structures, orcage structures, or mixtures of all three. Cyclic aluminoxane compoundshaving the formula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and p is an integer from 3 to 20, are encompassed by thisdisclosure. The AIRO moiety shown here also constitutes the repeatingunit in a linear aluminoxane. Thus, linear aluminoxanes having theformula:

wherein R is a linear or branched alkyl having from 1 to 10 carbonatoms, and q is an integer from 1 to 50, are also encompassed by thisdisclosure. Further, aluminoxanes suitable for use in this disclosurecan have cage structures of the formula R^(t) _(5r+α)R^(b)_(r−α)Al_(4r)O_(3r), wherein R^(t) is a terminal linear or branchedalkyl group having from 1 to 10 carbon atoms; R^(b) is a bridging linearor branched alkyl group having from 1 to 10 carbon atoms; r is 3 or 4;and α is equal to n_(Al(3))−n_(O(2))+n_(O(4)), wherein n_(Al(3)) is thenumber of three coordinate aluminum atoms, n_(O(2)) is the number of twocoordinate oxygen atoms, and n_(O(4)) is the number of 4 coordinateoxygen atoms.

In an embodiment, aluminoxanes which can be employed as additionalactivators in the catalyst compositions of the present disclosure arerepresented generally by formulas such as (R—Al—O)_(p),R(R—Al—O)_(q)AlR₂, and the like. In these formulas, the R group istypically a linear or branched C₁-C₆ alkyl, such as methyl, ethyl,propyl, butyl, pentyl, or hexyl. Examples of aluminoxane compounds thatcan be used in accordance with the present disclosure include, but arenot limited to, methylaluminoxane, ethylaluminoxane,n-propylaluminoxane, iso-propyl-aluminoxane, n-butylaluminoxane,t-butylaluminoxane, sec-butylaluminoxane, iso-butylaluminoxane,1-pentylaluminoxane, 2-pentylaluminoxane, 3-pentylaluminoxane,isopentyl-aluminoxane, neopentylaluminoxane, and the like, or anycombination thereof. Methylaluminoxane, ethylaluminoxane, andiso-butylaluminoxane are prepared from trimethylaluminum,triethylaluminum, or triisobutylaluminum, respectively, and sometimesare referred to as poly(methyl aluminum oxide), poly(ethyl aluminumoxide), and poly(isobutyl aluminum oxide), respectively. It is alsowithin the scope of the disclosure to use an aluminoxane in combinationwith a trialkylaluminum, such as that disclosed in U.S. Pat. No.4,794,096, incorporated herein by reference in its entirety.

The present disclosure contemplates many values of p and q in thealuminoxane formulas (R—Al—O)_(p) and R(R—Al—O)_(q)AlR₂, respectively.In some aspects, p and q are at least 3. However, depending upon how theorganoaluminoxane is prepared, stored, and used, the value of p and qcan vary within a single sample of aluminoxane, and such combinations oforganoaluminoxanes are contemplated herein.

In preparing a catalyst composition containing an aluminoxane, the molarratio of the total moles of aluminum in the aluminoxane (oraluminoxanes) to the total moles of transition metal complex in thecomposition is generally between about 1:10 and about 100,000:1;alternatively, in a range from about 5:1 to about 15,000:1. Optionally,aluminoxane can be added to a polymerization zone in ranges from about0.01 mg/L to about 1000 mg/L, from about 0.1 mg/L to about 100 mg/L, orfrom about 1 mg/L to about 50 mg/L.

In an embodiment, the additional activator comprises comprise anorganoboron compound or an organoborate compound. Organoboron ororganoborate compounds include neutral boron compounds, borate salts,and the like, or combinations thereof. For example, fluoroorgano boroncompounds and fluoroorgano borate compounds are contemplated.

Any fluoroorgano boron or fluoroorgano borate compound can be utilizedwith the present disclosure. Examples of fluoroorgano borate compoundsthat can be used in the present disclosure include, but are not limitedto, fluorinated aryl borates such as N,N-dimethylaniliniumtetrakis(pentafluorophenyl)borate, triphenylcarbeniumtetrakis(pentafluorophenyl)borate, lithiumtetrakis(pentafluorophenyl)borate, N,N-dimethylaniliniumtetrakis[3,5-bis(trifluoro-methyl)phenyl]borate, triphenylcarbeniumtetrakis[3,5-bis(trifluoromethyl)phenyl]borate, and the like, ormixtures thereof. Examples of fluoroorgano boron compounds that can beused in the present disclosure include, but are not limited to,tris(pentafluorophenyl)boron, tris[3,5-bis(trifluoromethyl)phenyl]boron,and the like, or mixtures thereof. Although not intending to be bound bythe following theory, these examples of fluoroorgano borate andfluoroorgano boron compounds, and related compounds, are thought to form“weakly-coordinating” anions when combined with organometal compounds,as disclosed in U.S. Pat. No. 5,919,983, the disclosure of which isincorporated herein by reference in its entirety. Applicants alsocontemplate the use of diboron, or bis-boron, compounds or otherbifunctional compounds containing two or more boron atoms in thechemical structure, such as disclosed in J. Am. Chem. Soc., 2005, 127,pp. 14756-14768, the content of which is incorporated herein byreference in its entirety.

Generally, any amount of organoboron compound can be used. According toone aspect of this disclosure, the molar ratio of the total moles oforganoboron or organoborate compound (or compounds) to the total molesof metallocene compound (or compounds) in the catalyst composition is ina range from about 0.1:1 to about 15:1. Typically, the amount of thefluoroorgano boron or fluoroorgano borate compound used is from about0.5 moles to about 10 moles of boron/borate compound per mole oftransition metal complex compound. According to another aspect of thisdisclosure, the amount of fluoroorgano boron or fluoroorgano boratecompound is from about 0.8 moles to about 5 moles of boron/boratecompound per mole of transition metal complex.

A catalyst system for preparation of a BIP may further comprise acocatalyst. In an embodiment, the cocatalyst comprises an organoaluminumcompound. Such compounds include, but are not limited to, compoundshaving the formula:(R¹)₃Al;where R¹ is an aliphatic group having from 2 to 10 carbon atoms. Forexample, R¹ can be ethyl, propyl, butyl, hexyl, or isobutyl.

Other organoaluminum compounds which can be used in catalystcompositions disclosed herein can include, but are not limited to,compounds having the formula:Al(X¹)_(m)(X²)_(3-m),where X¹ is a hydrocarbyl; X² is an alkoxide or an aryloxide, a halide,or a hydride; and m is from 1 to 3, inclusive. In an embodiment, X¹ is ahydrocarbyl having from 1 to about 20 carbon atoms; alternatively from 1to 10 carbon atoms. Nonlimiting examples of such hydrocarbyls have beenpreviously disclosed herein. In an embodiment, X² is an alkoxide or anaryloxide, any one of which has from 1 to 20 carbon atoms, a halide, ora hydride. In an embodiment, X² is selected independently from fluorineor chlorine, alternatively, X² is chlorine. In the formula,Al(X¹)_(m)(X²)_(3-m) may be a number from 1 to 3, inclusive,alternatively, m is 3. The value of m is not restricted to be aninteger; therefore, this formula includes sesquihalide compounds orother organoaluminum cluster compounds.

Examples of organoaluminum compounds suitable for use in accordance withthe present disclosure include, but are not limited to, trialkylaluminumcompounds, dialkylaluminum halide compounds, dialkylaluminum alkoxidecompounds, dialkylaluminum hydride compounds, and combinations thereof.Specific non-limiting examples of suitable organoaluminum compoundsinclude trimethylaluminum (TMA), triethylaluminum (TEA),tri-n-propylaluminum (TNPA), tri-n-butylaluminum (TNBA),triisobutylaluminum (TIBA), tri-n-hexylaluminum, tri-n-octylaluminum,diisobutylaluminum hydride, diethylaluminum ethoxide, diethylaluminumchloride, and the like, or combinations thereof.

Generally, the weight ratio of organoaluminum compound toactivator-support is in a range from about 10:1 to about 1:1000. If morethan one organoaluminum compound and/or more than one activator-supportis employed, this ratio is based on the total weight of each respectivecomponent. In another embodiment, the weight ratio of the organoaluminumcompound to the activator-support is in a range from about 3:1 to about1:100, or from about 1:1 to about 1:50.

In an embodiment catalyst system for preparation of a BIP of the typedescribed herein comprises Cp*Cr(CH₃)₂(py), a sulfated alumina activatorsupport, an optional activator comprising an aluminoxane and an optionalcocatalyst comprising an organoaluminum compound. In an embodimentcatalyst system for preparation of a BIP of the type described hereincomprises Cp′Cr(Cl)₂(THF); a sulfated alumina activator support, anoptional activator comprising an aluminoxane and an optional cocatalystcomprising an organoaluminum compound. In an embodiment catalyst systemfor preparation of a BIP of the type described herein comprisesCp″Cr(Cl)₂(THF), a sulfated alumina activator support, an optionalactivator comprising an aluminoxane and an optional cocatalystcomprising an organoaluminum compound.

The catalyst and catalyst systems disclosed herein are intended for anyolefin polymerization method which may be carried out using varioustypes of polymerization reactors. As used herein, “polymerizationreactor” includes any polymerization reactor capable of polymerizingolefin monomers to produce homopolymers or copolymers. Such homopolymersand copolymers are referred to as resins or polymers.

The various types of reactors include those that may be referred to asbatch, slurry, gas-phase, solution, high pressure, tubular or autoclavereactors. Gas phase reactors may comprise fluidized bed reactors orstaged horizontal reactors. Slurry reactors may comprise vertical orhorizontal loops. High pressure reactors may comprise autoclave ortubular reactors. Reactor types can include batch or continuousprocesses. Continuous processes could use intermittent or continuousproduct discharge. Processes may also include partial or full directrecycle of un-reacted monomer, un-reacted co-monomer, and/or diluent.

Polymerization reactor systems of the present disclosure may compriseone type of reactor in a system or multiple reactors of the same ordifferent type. Production of polymers in multiple reactors may includeseveral stages in at least two separate polymerization reactorsinterconnected by a transfer device making it possible to transfer thepolymers resulting from the first polymerization reactor into the secondreactor. The desired polymerization conditions in one of the reactorsmay be different from the operating conditions of the other reactors.Alternatively, polymerization in multiple reactors may include themanual transfer of polymer from one reactor to subsequent reactors forcontinued polymerization. Multiple reactor systems may include anycombination including, but not limited to, multiple loop reactors,multiple gas reactors, a combination of loop and gas reactors, multiplehigh pressure reactors or a combination of high pressure with loopand/or gas reactors. The multiple reactors may be operated in series orin parallel.

According to one aspect of the disclosure, the polymerization reactorsystem may comprise at least one loop slurry reactor comprising verticalor horizontal loops. Monomer, diluent, catalyst and optionally anyco-monomer may be continuously fed to a loop reactor wherepolymerization occurs. Generally, continuous processes may comprise thecontinuous introduction of a monomer, a catalyst, and a diluent into apolymerization reactor and the continuous removal from this reactor of asuspension comprising polymer particles and the diluent. Reactoreffluent may be flashed to remove the solid polymer from the liquidsthat comprise the diluent, monomer and/or co-monomer. Varioustechnologies may be used for this separation step including but notlimited to, flashing that may include any combination of heat additionand pressure reduction; separation by cyclonic action in either acyclone or hydrocyclone; or separation by centrifugation.

A typical slurry polymerization process (also known as the particle formprocess), is disclosed, for example, in U.S. Pat. Nos. 3,248,179;4,501,885; 5,565,175; 5,575,979; 6,239,235; 6,262,191; and 6,833,415,each of which is incorporated by reference herein in its entirety.

Suitable diluents used in slurry polymerization include, but are notlimited to, the monomer being polymerized and hydrocarbons that areliquids under reaction conditions. Examples of suitable diluentsinclude, but are not limited to, hydrocarbons such as propane,cyclohexane, isobutane, n-butane, n-pentane, isopentane, neopentane, andn-hexane. Some loop polymerization reactions can occur under bulkconditions where no diluent is used. An example is polymerization ofpropylene monomer as disclosed in U.S. Pat. No. 5,455,314, which isincorporated by reference herein in its entirety.

According to yet another aspect of this disclosure, the polymerizationreactor may comprise at least one gas phase reactor. Such systems mayemploy a continuous recycle stream containing one or more monomerscontinuously cycled through a fluidized bed in the presence of thecatalyst under polymerization conditions. A recycle stream may bewithdrawn from the fluidized bed and recycled back into the reactor.Simultaneously, polymer product may be withdrawn from the reactor andnew or fresh monomer may be added to replace the polymerized monomer.Such gas phase reactors may comprise a process for multi-step gas-phasepolymerization of olefins, in which olefins are polymerized in thegaseous phase in at least two independent gas-phase polymerization zoneswhile feeding a catalyst-containing polymer formed in a firstpolymerization zone to a second polymerization zone. One type of gasphase reactor is disclosed in U.S. Pat. Nos. 5,352,749; 4,588,790; and5,436,304, each of which is incorporated by reference herein in itsentirety.

According to still another aspect of the disclosure, a high pressurepolymerization reactor may comprise a tubular reactor or an autoclavereactor. Tubular reactors may have several zones where fresh monomer,initiators, or catalysts are added. Monomer may be entrained in an inertgaseous stream and introduced at one zone of the reactor. Initiators,catalysts, and/or catalyst components may be entrained in a gaseousstream and introduced at another zone of the reactor. The gas streamsmay be intermixed for polymerization. Heat and pressure may be employedappropriately to obtain optimal polymerization reaction conditions.

According to yet another aspect of the disclosure, the polymerizationreactor may comprise a solution polymerization reactor wherein themonomer is contacted with the catalyst composition by suitable stirringor other means. A carrier comprising an inert organic diluent or excessmonomer may be employed. If desired, the monomer may be brought in thevapor phase into contact with the catalytic reaction product, in thepresence or absence of liquid material. The polymerization zone ismaintained at temperatures and pressures that will result in theformation of a solution of the polymer in a reaction medium. Agitationmay be employed to obtain better temperature control and to maintainuniform polymerization mixtures throughout the polymerization zone.Adequate means are utilized for dissipating the exothermic heat ofpolymerization.

Polymerization reactors suitable for the present disclosure may furthercomprise any combination of at least one raw material feed system, atleast one feed system for catalyst or catalyst components, and/or atleast one polymer recovery system. Suitable reactor systems for thepresent disclosure may further comprise systems for feedstockpurification, catalyst storage and preparation, extrusion, reactorcooling, polymer recovery, fractionation, recycle, storage, loadout,laboratory analysis, and process control.

Conditions that are controlled for polymerization efficiency and toprovide resin properties include temperature, pressure and theconcentrations of various reactants. Polymerization temperature canaffect catalyst productivity, polymer molecular weight and molecularweight distribution. Suitable polymerization temperature may be anytemperature below the de-polymerization temperature according to theGibbs Free energy equation. Typically this includes from about 60° C. toabout 280° C., for example, and from about 70° C. to about 110° C.,depending upon the type of polymerization reactor.

Suitable pressures will also vary according to the reactor andpolymerization type. The pressure for liquid phase polymerizations in aloop reactor is typically less than 1000 pound-force per square inchgauge (psig). Pressure for gas phase polymerization is usually at about200 to about 500 psig. High pressure polymerization in tubular orautoclave reactors is generally run at about 20,000 to about 75,000psig. Polymerization reactors can also be operated in a supercriticalregion occurring at generally higher temperatures and pressures.Operation above the critical point of a pressure/temperature diagram(supercritical phase) may offer advantages.

The concentration of various reactants can be controlled to produceresins with certain physical and mechanical properties. The proposedend-use product that will be formed by the resin and the method offorming that product determines the desired resin properties. Mechanicalproperties include tensile, flexural, impact, creep, stress relaxationand hardness tests. Physical properties include density, molecularweight, molecular weight distribution, melting temperature, glasstransition temperature, temperature melt of crystallization, density,stereoregularity, crack growth, long chain branching and rheologicalmeasurements.

The concentrations of monomer, hydrogen, modifiers, and electron donorsare important in producing these resin properties. Hydrogen can be usedto control product molecular weight. Modifiers can be used to controlproduct properties and electron donors affect stereoregularity. Inaddition, the concentration of poisons is minimized because poisonsimpact the reactions and product properties. In an embodiment, hydrogenis added to the reactor during polymerization. Alternatively, hydrogenis not added to the reactor during polymerization.

The polymer or resin may be formed into various articles, including, butnot limited to, bottles, drums, toys, household containers, utensils,film products, drums, fuel tanks, pipes, geomembranes, and liners.Various processes may be used to form these articles, including, but notlimited to, blow molding, extrusion molding, rotational molding,injection molding, fiber spinning, thermoforming, cast molding and thelike. After polymerization, additives and modifiers can be added to thepolymer to provide better processing during manufacturing and fordesired properties in the end product. Additives include surfacemodifiers such as slip agents, antiblocks, tackifiers; antioxidants suchas primary and secondary antioxidants; pigments; processing aids such aswaxes/oils and fluoroelastomers; and special additives such as fireretardants, antistats, scavengers, absorbers, odor enhancers, anddegradation agents.

Catalysts and catalyst systems prepared in accordance with the presentdisclosure may be used for the polymerization of olefins, for example,alpha-olefins. In an embodiment, a catalyst or catalyst system of thetype described herein is contacted with an olefin in a reaction zoneunder suitable reaction conditions (e.g., temperature, pressure, etc.)to polymerize the olefins. Linear or branched alpha-olefins having 2 to30 carbon atoms can be used as the olefins raw material. Specificexamples of the alpha-olefins may include ethylene, propylene, 1-butene,1-hexene, 1-octene, 3-methyl-1-butene, 4-methyl-1-pentene, or the like.Such alpha-olefins may be used individually to produce homopolymers. Inan embodiment, the catalyst system described herein is used to producepolyethylene, for example, a polyethylene homopolymer or co-polymer.

After polymerization, additives and modifiers can be added to thepolymer to provide better processing during manufacturing and fordesired properties in the end product. Additives include surfacemodifiers such as slip agents, antiblocks, tackifiers; antioxidants suchas primary and secondary antioxidants; pigments; processing aids such aswaxes/oils and fluoroelastomers; and special additives such as fireretardants, antistats, scavengers, absorbers, odor enhancers, anddegradation agents.

In an embodiment, a catalyst system of the type described herein whenused as a polymerization catalyst may display a catalyst activity in therange of from about 10,000 g (PE)/g (Cr)/h to about 5,000,000 g (PE)/g(Cr)/h; alternatively, from about 20,000 g (PE)/g (Cr)/h to about4,000,000; alternatively, from about 30,000 g (PE)/g (Cr)/h to about3,000,000 g (PE)/g (Cr)/h. Catalyst activity is described in terms ofgrams polyethylene produced per gram of chromium-catalyst per hour (g(PE)/g Cr/h). In an embodiment, the catalyst activity is independent ofthe reaction temperature in the range of from about 60° C. to about 120°C.; alternatively from about 70° C. to about 115° C.; alternatively fromabout 80° C. to about 110° C. Herein “independent of the reactiontemperature” refers to the catalyst activity varying by less than about20%, alternatively less than about 15%; alternatively less than about10% in the disclosed ranges.

In an embodiment, a BIP of the type described herein is a unimodalresin. Herein, the “modality” of a polymer resin refers to the form ofits molecular weight distribution curve, i.e., the appearance of thegraph of the polymer weight fraction as a function of its molecularweight. The polymer weight fraction refers to the weight fraction ofmolecules of a given size. A polymer having a molecular weightdistribution curve showing a single peak may be referred to as aunimodal polymer, a polymer having curve showing two distinct peaks maybe referred to as bimodal polymer, a polymer having a curve showingthree distinct peaks may be referred to as trimodal polymer, etc. Two ormore peaks may be referred to as multimodal.

In an embodiment, the BIP has a weight average molecular weight (M_(w))of from about 10,000 g/mol to about 2,500,000 g/mol, alternatively fromabout 50,000 g/mol to about 2,000,000 g/mol; or alternatively from about100,000 g/mol to about 1,500,000 g/mol; or alternatively, from about140,000 g/mol to about 160,000 g/mol and a number average molecularweight (M_(n)) of from about 3,000 g/mol to about 150,000 g/mol,alternatively, from about 4,000 g/mol to about 125,000 g/mol,alternatively, from about 5,000 g/mol to about 100,000 g/mol; oralternatively, from about 8,000 g/mol to about 18,000 g/mol. The weightaverage molecular weight describes the molecular weight distribution ofa polymer composition and is calculated according to equation 1:

$\begin{matrix}{{\overset{\_}{M}}_{w} = \frac{\sum\limits_{i}\;{N_{i}M_{i}^{2}}}{\sum\limits_{i}\;{N_{i}M_{i}}}} & (1)\end{matrix}$where Ni is the number of molecules of molecular weight Mi. Allmolecular weight averages are expressed in gram per mole (g/mol). Thenumber average molecular weight is the common average of the molecularweights of the individual polymers calculated by measuring the molecularweight of n polymer molecules, summing the weights, and dividing by n.

$\begin{matrix}{{\overset{\_}{M}}_{n} = \frac{\sum\limits_{i}\;{N_{i}M_{i}}}{\sum\limits_{i}\; N_{i}}} & (2)\end{matrix}$

The molecular weight distribution (MWD) of the BIP is the ratio of theweight average molecular weight (M_(w)) to the number average molecularweight (M_(n)), which is also referred to as the polydispersity index(PDI) or more simply as polydispersity. The BIP composition may becharacterized by a broad molecular weight distribution (MWD). Morespecifically, the BIP composition may have a PDI from about 2 to about120, alternatively from about 3 to about 100, alternatively from about 4to about 80.

The BIP may be characterized by the degree of branching present in thecomposition. Short chain branching (SCB) is known for its effects onpolymer properties such as stiffness, tensile properties, heatresistance, hardness, permeation resistance, shrinkage, creepresistance, transparency, stress crack resistance, flexibility, impactstrength, and the solid state properties of semi-crystalline polymers,such as polyethylene, while long chain branching (LCB) exerts itseffects on polymer rheology. The BIP composition may contain equal to orless than about one long chain branch (LCB) per about 10,000 totalcarbon atoms (about 1/10,000), alternatively, equal to or less thanabout one LCB per about 100,000 total carbon atoms (about 1/100,000), oralternatively, equal to or less than about one LCB per about 1,000,000total carbon atoms (about 1/1,000,000). In an aspect, LCB in the BIP maybe increased using any suitable methodology such as, for example, bytreatment with peroxide. In an aspect, the BIP is treated to increasethe LCB to from greater than about 0 to about 0.5, alternatively, fromgreater than about 0 to about 0.25, alternatively, from greater thanabout 0 to about 0.15, or alternatively, from about 0.01 to about 0.08.

In an embodiment, a BIP of the type described herein is characterized bya density of from about 0.946 g/ml to about 0.97 g/ml, alternatively,from about 0.948 g/ml to about 0.968 g/ml, alternatively, from about0.95 g/ml to about 0.966 g/ml, or alternatively, from about 0.96 g/ml toabout 0.966 g/ml as determined in accordance with ASTM D1505. Forexample, the BIP may be a high-density polyethylene having a density ofgreater than about 0.945 g/ml, alternatively, greater than about 0.955g/ml, alternatively, greater than about 0.958 g/ml.

In an embodiment, a BIP produced using a catalyst of the type describedherein has a melt index, MI, in the range of from about 0.01 dg/min. toabout 5.0 dg/min., alternatively, from about 0.05 dg/min. to about 4.0dg/min., alternatively, from about 0.1 dg/min. to about 3.0 dg/min, oralternatively, from about 0.8 dg/min. to about 1.8 dg/min. The meltindex (MI) refers to the amount of a polymer which can be forced throughan extrusion rheometer orifice of 0.0825 inch diameter when subjected toa force of 2160 grams in ten minutes at 190° C., as determined inaccordance with ASTM D 1238.

In an embodiment, a BIP of the type described herein has a CarreauYasuda ‘a’ parameter in the range of from about 0.1 to about 0.3,alternatively, from about 0.5 to about 0.6, alternatively, from about0.51 to about 0.59, alternatively, from about 0.54 to about 0.57. TheCarreau Yasuda ‘a’ parameter (CY-a) is defined as the rheologicalbreadth parameter. Rheological breadth refers to the breadth of thetransition region between Newtonian and power-law type shear rate for apolymer or the frequency dependence of the viscosity of the polymer. Therheological breadth is a function of the relaxation time distribution ofa polymer resin, which in turn is a function of the resin molecularstructure or architecture. The CY-a parameter may be obtained byassuming the Cox-Merz rule and calculated by fitting flow curvesgenerated in linear-viscoelastic dynamic oscillatory frequency sweepexperiments with a modified Carreau-Yasuda (CY) model, which isrepresented by Equation (3):

$\begin{matrix}{E = {E_{o}\left\lbrack {1 + \left( {T_{\xi}} \right)^{a}} \right\rbrack}^{\frac{n - 1}{a}}} & (3)\end{matrix}$

where

E=viscosity (Pa·s)

=shear rate (1/s)

a=rheological breadth parameter

T_(ξ)=relaxation time (s) [describes the location in time of thetransition region]

E_(o)=zero shear viscosity (Pa·s) [defines the Newtonian plateau]

n=power law constant [defines the final slope of the high shear rateregion].

To facilitate model fitting, the power law constant n is held at aconstant value. Details of the significance and interpretation of the CYmodel and derived parameters may be found in: C. A. Hieber and H. H.Chiang, Rheol. Acta, 28, 321 (1989); C. A. Hieber and H. H. Chiang,Polym. Eng. Sci., 32, 931 (1992); and R. B. Bird, R. C. Armstrong and O.Hasseger, Dynamics of Polymeric Liquids, Volume 1, Fluid Mechanics, 2ndEdition, John Wiley & Sons (1987), each of which is incorporated byreference herein in its entirety.

In an embodiment, a BIP of the type described herein has a zero shearviscosity (E_(o)), defined by Equation (3), in the range of from about3.5×10³ Pa-s to about 7×10⁴ Pa-s, alternatively from about 1×10⁴ Pa-s toabout 6×10⁴ Pa-s, alternatively from about 1.5×10⁴ Pa-s to about 6×10⁴Pa-s. The zero shear viscosity refers to the viscosity of the polymericcomposition at a zero shear rate and is indicative of the materialsmolecular structure. Further, for polymer melts, the zero shearviscosity is often a useful indicator of processing attributes such asmelt strength in blow-molding and foam technologies and bubble stabilityin film blowing. For example, the higher the zero shear viscosity, thebetter the melt strength or bubble stability.

In an embodiment, a BIP of the type described herein has a relaxationtime (τ), defined by Equation (3), in the range of from about 0.01 s toabout 0.10 s, alternatively, from about 0.01 s to about 0.03 s,alternatively, from about 0.012 s to about 0.08 s, alternatively, fromabout 0.015 s to about 0.05 s. The relaxation rate refers to the viscousrelaxation times of the polymer and is indicative of a distribution ofrelaxation times associated with the wide distribution of molecularweights.

In an embodiment, a BIP of the type described herein has a shearviscosity at 100 sec⁻¹ (E₁₀₀), defined as the viscosity indicative ofthe head pressure during extrusion, in the range of from about 8×10²Pa-s to about 6×10⁴ Pa-s, alternatively, from about 8×10² Pa-s to about2×10³ Pa-s, alternatively, from about 8×10² Pa-s to about 1.2×10³ Pa-s,alternatively, from about 8.5×10² Pa-s to about 1.9×10³ Pa-s,alternatively, from about 9×10² Pa-s to about 1.8×10³ Pa-s, oralternatively, from about 1×10⁴ Pa-s to about 6×10⁴ Pa-s. This featureis related to the ease of extrusion during the film fabrication and isan indirect comparative measurement of the head pressure generated bythe melt extrusion of the polymer in an extruder. In general, a lowerhead pressure is favorable to higher output rates, i.e., more pounds ofmaterial produced per hour of extrusion.

Polymer resins produced as disclosed herein may be formed into articlesof manufacture or end use articles using techniques known in the artsuch as extrusion, blow molding, injection molding, fiber spinning,thermoforming, and casting. For example, a polymer resin may be extrudedinto a sheet, which is then thermoformed into an end use article such asa container, a cup, a tray, a pallet, a toy, or a component of anotherproduct. In an embodiment, the polymer resins produced as describedherein (e.g., polyethylene) may be formed into films which can be usefulin food packaging.

In an embodiment, the polymer resins of this disclosure are fabricatedinto a film. The films of this disclosure may be produced by anysuitable method and under any suitable condition for the production offilms. In an embodiment, the polymer resins are formed into filmsthrough a cast film process. In a cast film process, plastic melt isextruded through a slit die onto a chilled, polished roll to freeze thefilm. The speed of the roll controls the draw down ratio and film gauge.The film moves forward toward a second wounding roll where cooling iscompleted. The films formed from polymer resins of this disclosure(e.g., polyethylene) may be of any thickness desired by the user.Alternatively, the polymer resins of this disclosure may be formed intofilms having a thickness of from about 0.3 mil (7 microns) to about 3mils (76 microns), alternatively, from about 0.5 mil (12 microns) toabout 2 mils (50 microns), alternatively, from about 0.8 mil (20microns) to about 1.6 mils (40 microns).

Production of films of the type described herein may be facilitated bythe use of polymeric resins prepared as described herein. For example,polymeric resins of the type described herein (i.e., BIP) when subjectedto the film production process may display improved processingcharacteristics. In an embodiment, polymer resins of the type describedherein may be extruded at a similar extrusion pressure when compared topolymer resin of similar melt index prepared with a dissimilar catalystsystem. Such dissimilar catalysts may be conventional catalyst systemssuch as Ziegler Natta catalysts.

Additional observations in processing may include similar head pressuresand motor load are employed in the manufacture process with the resinsof this disclosure when compared to resins produced using dissimilarcatalyst systems. Herein the head pressure refers to the dischargepressure at the end of the extruder while the motor load refers tohorsepower draw of the extruder.

In an embodiment, the BIP comprises a polyethylene homopolymer which isformed into a film that displays enhanced barrier properties. Forexample said films may display a reduced moisture vapor transmissionrate (MVTR).

In an embodiment, a nominally 1.6-1.8 mil thick blown film produced frompolymer resins of this disclosure (i.e., BIP) has a gauge-normalizedMVTR in the range of from about 0.30 grams·mil per 100 square inch perday (g·mil/100 in²/day) to about 0.85 g·mil/100 in²/day, alternatively,from about 0.3 g·mil/100 in²/day to about 0.6 g·mil/100 in²/day, oralternatively, from about 0.3 g·mil/100 in²/day to about 0.5 g·mil/100in²/day as measured in accordance with ASTM F 1249. The MVTR measurespassage of gaseous H₂O through a barrier. The MVTR may also be referredto as the water vapor transmission rate (WVTR). Typically, the MVTR ismeasured in a special chamber, divided vertically by thesubstrate/barrier material. A dry atmosphere is in one chamber, and amoist atmosphere is in the other. A 24-hour test is run to see how muchmoisture passes through the substrate/barrier from the “wet” chamber tothe “dry” chamber under conditions which can specify any one of fivecombinations of temperature and humidity in the “wet” chamber.

EXAMPLES

The subject matter having been generally described, the followingexamples are given as particular embodiments of the disclosure and todemonstrate the practice and advantages thereof. It is understood thatthe examples are given by way of illustration and are not intended tolimit the specification of the claims to follow in any manner. In thefollowing examples, MVTR was measured in accordance with ASTM F-1249.Following the extrusion of the resin into film, the actual measurementof MVTR is performed using a Mocon Permatran machine (model W 3/31)testing system or equivalent. The Mocon instrument for measuring waterpermeability was developed by Modern Controls, Inc. To accomplish theMVTR measurement, a 10×10 cm sample is cut from a random area of thefilm. The sample is then mounted in a sample test cell and placed in theMocon Permatran W3/31 unit. In the unit, the test film is exposed to aconstant continuous flow of dry nitrogen gas across one side of the film(exhaust side) and a constant flow of controlled humidity nitrogen gasacross the other side (carrier side). Water vapor passes from thehumidified nitrogen side of the test cell through the film and into thedry nitrogen side of the test cell. A modulated infra-redphoto-detection system on the exhaust side of the test cell measures thevariation in absorption of infra-red energy caused by the water vaporwhich has transmitted through the film. By comparing the amplitude ofthe output signal obtained from the infra-red photo-detection systemmounted on the test cell with the amplitude of a signal from a referencecell in the same instrument containing a film with a known transmissionrate, the transmission rate of the test film is determined. Byconvention, the value obtained from MVTR is expressed as grams of watertransmitted per 100 square inches per one mil (one thousandth of aninch) thickness in a 24-hour period (or, in metric system, grams ofwater transmitted per square meter per mm thickness in a 24-hourperiod).

Example 1

Catalyst systems of the type described herein comprising a half-sandwichchromium transition metal complex, a sulfated alumina support and anoptional TIBA cocatalyst were prepared. All manipulations were performedunder purified nitrogen atmosphere using standard Schlenk line orglovebox techniques. The solvent THF was distilled from potassium, whileanhydrous diethyl ether, heptane, pyridine and toluene (FisherScientific Company) were stored over activated alumina. All solventswere degassed and stored under nitrogen. Chromium (III) trichloride andall of the organic ligands were purchased from Aldrich Chemical Company.Li(η⁵-C₅H₄CH₂CH₂CH═CH₂) was prepared by the method describe in Brieger,et al., J. Org. Chem. 36 (1971) p 243, and Li(η⁵-C₅H₄C(Me)₂CH₂CH₂CH═CH₂)was prepare according to the method used by Bochmann, et al. in J.Organmet. Chem. 592 (1999). Complex (I), Cp*Cr(CH₃)₂(py), was preparedby the procedure described in Theopold, et al. J. Am. Chem. Soc. 111(1989) p 9127.

Complex (II) which was Cp′Cr(Cl)₂(THF) (Cp′=η⁵-C₅H₄CH₂CH₂CH═CH₂) wasprepared by a procedure involving adding to a THF solution of CrCl₃.3THF(1.5 grams, 4.0 mmol) 1 equiv of Li(η⁵-C₅H₄CH₂CH₂CH═CH₂) (0.5 grams, 4.0mmol) in THF at 0° C. The mixture was stirred at room temperature for 5hours. After the THF was removed under vacuum, the blue crystal wasobtained in a mixture solvent of toluene and heptane at −35° C. (0.3grams, yield: 31%). Complex (III) which was Cp″Cr(Cl)₂(THF)(Cp″=η⁵-C₅H₄C(Me)₂CH₂CH₂CH═CH₂) was prepared by a procedure involvingadding to a THF solution of CrCl₃.3THF (1.5 grams, 4.0 mmol) 1 equiv ofLi(η⁵-C₅H₄C(Me)₂CH₂CH₂CH═CH₂) (0.678 grams, 4.0 mmol) in THF at 0° C.The mixture was stirred at room temperature for 5 hours. After the THFwas removed under vacuum, the blue crystal was obtained in a mixturesolvent of heptanes at −35° C. (0.32 grams, yield: 28%).

The sulfated solid oxide activator support (SSA) was prepared usingAlumina A, from W.R. Grace Company, which was impregnated to incipientwetness with an aqueous solution of ammonium sulfate. Typically, thealumina had a surface area of about 330 m²/gram and a pore volume ofabout 1.3 cc/gram. The amount of ammonium sulfate used was equal to 20%of the starting alumina. The volume of water used to dissolve theammonium sulfate was calculated from the total pore volume of thestarting sample (i.e. 2.6 mL of water for each gram of alumina to betreated). Thus, a solution of about 0.08 grams of ammonium sulfate permL of water was employed. The resulting wet sand was dried in a vacuumoven overnight at 120° C., and then screened through a 35 mesh screen.Finally, the material was activated in a fluidizing stream of dry air at550° C. for 6 hours. The samples were then stored under nitrogen.

Catalyst systems comprising Complex (I), (II), or (III), the SSA and acocatalyst were utilized in the polymerization of ethylene. Generally,all polymerizations were carried out for one hour in a one gallon (3.785liter) stainless-steel autoclave reactor containing two liters ofisobutane as diluent, and hydrogen added from a 325 cc auxiliary vessel.Delta P of hydrogen refers to the pressure drop in that vessel from 600psig starting pressure. Chromium based half sandwich solutions (1 mg/mL)were usually prepared by dissolving 20 mg of the catalysts precursors in20 mL of toluene. The reactor was maintained at desired run temperaturethrough the run by an automated heating-cooling system.

The polymerization procedure could be carried out using one of twogeneral protocols. Using protocol 1, under isobutane purge a TIBAsolution (25% in heptanes) was charged to a cold reactor followed by amixture of half-sandwich chromium complexes and sulfated SSA in toluene.The reactor was closed and 2 Liters isobutane were added. The reactorwas quickly heated to within 5 degrees of the run temperature and theethylene feed was opened, ethylene was fed on demand to maintain thereactor pressure. Hydrogen was then introduced into the reactor duringthe polymerization process. For copolymerization, 1-hexene was flushedin with the initial ethylene charge. At the end of one hour, the reactorcontents were flared; the reactor was purged with nitrogen, and thenopened. The polymer powder was dried overnight at 60° C. under vacuum.Using protocol II, under isobutane purge a mixture of TIBA solution (25%in heptanes) and SSA was charged to a cold reactor followed byhalf-sandwich chromium compounds in toluene. The reactor was closed and2 Liters isobutane were added. The reactor was quickly heated to within5 degrees of the run temperature and the ethylene feed was opened,ethylene was fed on demand to maintain the reactor pressure. Hydrogenwas then introduced into the reactor during the polymerization process.For copolymerization, 1-hexene was flushed in with the initial ethylenecharge. At the end of one hour, the reactor contents were flared; thereactor was purged with nitrogen, and then opened. The polymer powderwas dried overnight at 60° C. under vacuum.

For samples prepared using Complex (I) and a sulfated SSA activatorsupport, the polymerization process comprised mixing 0.2 mL of TIBA with0.15 grams of sulfated SSA in a glass tube under nitrogen. After aboutone minute, the slurry was added the reactor below 40° C. 0.001 gram ofCp*Cr(CH₃)₂(py) in 1 mL of toluene was also added to the reactor. Thereactor was sealed and 2 L of isobutane were added and stirring startedat 700 rpm. As the reactor temperature approached 100° C., H2 (366 psi)and ethylene (555 psi) addition was begun and set point of 105° C. wasthan rapidly attained. The reactor was held at 105° C. for 60 minutesand then the volatiles were vent to the flare system. This procedureleft the polyethylene solid in the reactor. It yielded 221.4 grams ofpolyethylene (activity, 1,262,069 g (PE)/g (Cr)/h).

For samples prepared using Complex (II) and a sulfated SSA activatorsupport, the polymerization process comprised adding 0.2 mL of TIBA, 0.3grams of sulfated SSA, and 0.002 grams of Cp′Cr(Cl)₂(THF)(Cp′=η⁵-C₅H₄CH₂CH₂CH═CH₂) in 1 mL of toluene to the reactor respectivelyunder 40° C. The reactor was sealed and 2 L of isobutane were added andstirring started at 700 rpm. As the reactor temperature approached 75°C., ethylene (550 psi) addition was begun and set point of 80° C. wasthan rapidly attained. The reactor was held at 80° C. for 60 minutes andthen the volatiles were vent to the flare system. This procedure leftthe polyethylene solid in the reactor. It yielded 358.6 grams ofpolyethylene (activity, 1,083,455 g (PE)/g (Cr)/h).

For samples prepared using Complex (III) and a sulfated SSA activatorsupport, the polymerization process comprised adding 0.2 mL of TIBA, 0.3grams of sulfated SSA, and 0.002 grams of Cp″Cr(Cl)₂(THF)(Cp″=η⁵-C₅H₄C(Me)₂CH₂CH₂CH═CH₂) in 1 mL of toluene to the reactorrespectively under 40° C. The reactor was sealed and 2 L of isobutanewere added and stirring started at 700 rpm. As the reactor temperatureapproached 85° C., ethylene (402 psi) addition was begun and set pointof 90° C. was than rapidly attained. The reactor was held at 90° C. for60 minutes and then the volatiles were vent to the flare system. Thisprocedure left the polyethylene solid in the reactor. It yielded 108.1grams of polyethylene (activity, 366,163 g (PE)/g (Cr)/h).

A total of 48 samples were prepared and the conditions, components andcomponent amounts used in each sample, along with the catalyst activityare summarized in Table 1.

TABLE 1 Sample Catalysts TIBA SSA Comonomer Delta P H₂ Ethylene TempTime Activity Activity No. (gram) (mL) (gram) C6(grams) (psi) (psi) (°C.) (min) kgPE/mol/h gPE/gCr/h 1   I(0.002) 0.2 0.3 0 0 402 90 54 800271539099 2   I(0.002) 0.2 0.3 0 330 461 90 58 72454 1393453 3   I(0.001)0.2 0.15 0 461 486 90 60 43808 842519 4   I(0.001) 0.2 0.15 0 0 490 10560 70039 1347005 5   I(0.001) 0.2 0.15 0 463 490 105 60 55723 1071675 6  I(0.001) 0.2 0.15 0 263 536 105 60 40666 782095 7   I(0.001) 0.2 0.150 366 555 105 60 44578 857340 8   I(0.001) 0.2 0.15 0 366 555 105 6065623 1262069 9   I(0.001) 0.2 0.15 0 469 574 105 60 60050 1154901 10  I(0.001) 0.2 0.15 0 520 584 105 60 50417 969638 11   I(0.001) 0.2 0.1518 462 484 90 60 33226 639015 12   I(0.001) 0.2 0.15 38 463 484 90 6033315 640725 13   I(0.001) 0.2 0.15 57 463 482 90 60 34175 657256 14II(0.002) 0 0.3 0 0 402 90 30 0 0 15 II(0.002) 0.1 0.3 0 0 402 90 6014861 285820 16 II(0.002) 0.2 0.3 0 0 402 90 60 31200 600040 17II(0.002) 0.3 0.3 0 0 402 90 60 22999 442325 18 II(0.002) 0.5 0.3 0 0402 90 60 4619 88828 19 II(0.002) 1 0.3 0 0 402 90 60 24036 462266 20II(0.002) 2 0.3 0 0 402 90 60 21475 413018 21 II(0.001) 0.15 0 0 0 40290 60 0 0 22 II(0.002) 0.5 0.1 0 0 402 90 60 13715 263764 23 II(0.002)0.5 0.2 0 0 402 90 60 15521 298509 24 II(0 002) 0.5 0.3 0 0 402 90 6024554 472237 25 II(0.002) 0.5 0.4 0 0 402 90 60 24193 465288 26II(0.002) 0.5 0.2(M) 0 0 402 90 30 1650 31724 27 II(0.002) 0.5 0.3 0 0298 70 60 23643 454713 28 II(0.002) 0.5 0.3 0 0 348 80 60 25136 48341629 II(0.002) 0.5 0.3 0 0 460 100 60 25686 493990 30 II(0.002) 0.2 0.3 00 550 80 60 56335 1083455 31 II(0.002) 0.2 0.3 0 18 406 90 60 26235504565 32 II(0.002) 0.2 0.3 0 32 407 90 60 24774 476467 33 II(0.002) 0.20.3 0 59 409 90 70 27115 521485 34 II(0.002) 0.2 0.3 0 100 419 90 6024617 473445 35 II(0.002) 0.2 0.3 0 200 437 90 60 22811 438700 36II(0.002) 0.2 0.3 0 330 461 90 60 19889 382503 37 II(0.002) 0.2 0.3 10200 437 90 60 21978 422687 38 II(0.002) 0.2 0.3 20 200 437 90 60 17721340808 39 II(0.002) 0.2 0.3 30 200 437 90 60 18349 352893 40 II(0.002)0.2 0.3 50 200 437 90 60 15726 302437 41 II(0.002) 0.2 0.3 100 200 43790 60 13935 267994 42 II(0.002) 0.2 0.3 0 0 490 105 60 19135 368000 43II(0.002) 0.2 0.3 0 263 536 105 60 12961 249261 44 II(0.002) 0.2 0.3 0366 555 105 60 16165 310897 45 II(0.002) 0.2 0.3 0 366 555 105 60 18993365281 46 II(0.002) 0.2 0.3 0 469 574 105 60 13369 257117 47 II(0.002)0.2 0.3 0 469 574 105 60 17092 328723 48 III(0.002)   0.2 0.3 0 0 402 9060 19039 366163

The polymer samples were then subjected to additional characterization.Melt index (MI, g/10 min) was determined in accordance with ASTM D1238condition F at 190° C. with a 2,160 gram weight. High load melt index(HLMI, g/10 min) was determined in accordance with ASTM D1238 conditionE at 190° C. with a 21,600 gram weight. Polymer density was determinedin grams per cubic centimeter (g/cc) on a compression molded sample,cooled at about 15° C. per hour, and conditioned for about 40 hours atroom temperature in accordance with ASTM D1505 and ASTM D1928, procedureC. Molecular weights and molecular weight distributions were obtainedusing a PL 220 SEC high temperature chromatography unit (PolymerLaboratories) with trichlorobenzene (TCB) as the solvent, with a flowrate of 1 mL/minute at a temperature of 145° C. BHT(2,6-di-tert-butyl-4-methylphenol) at a concentration of 0.5 g/L wasused as a stabilizer in the TCB. An injection volume of 200 μL was usedwith a nominal polymer concentration of 1.5 mg/mL. Dissolution of thesample in stabilized TCB was carried out by heating at 150° C. for 5hours with occasional, gentle agitation. The columns used were threePLgel Mixed A LS columns (7.8×300 mm) and were calibrated with a broadlinear polyethylene standard (Chevron Phillips Marlex® BHB 5003) forwhich the molecular weight had been determined. The results of thesecharacterizations are summarized in Table 2.

TABLE 2 Sample Catalysts MI M_(n/)1000 M_(w)/1000 M_(z)/1000 Density No.(gram) dg/min HLMI (kg/mol) (kg/mol) (kg/mol) M_(w)/M_(n) (gram/cc) 1 I<0.01 <0.01 2 I <0.01 <0.01 3 I 0.11 24.14 220.4 935.4 9.13 0.9605 5 I<0.01 0.66 69.47 1382 3075 19.89 6 I 0.06 5.38 25.29 245.3 1212 9.70.9586 7 I 0.28 19.3 19.81 190.1 1094 9.6 0.9619 8 I 0.10 9.363 21.19271.9 2103 12.83 0.9608 9 I 0.40 21.16 18.39 170.9 1209 9.29 0.9628 10 I0.95 41.52 9.39 180.5 1898 19.22 0.9648 11 I 0.20 18.96 217.6 1256 11.480.9604 12 I 0.24 12.28 201.5 1386 16.41 0.9592 13 I 0.17 63.8 20.78214.9 1102 10.34 0.9578 20 II <0.01 <0.01 40.19 1146 3175 28.51 36 II<0.01 0.03 20.81 680.1 2305 32.68 41 II <0.01 <0.01 11.42 616.3 240853.96 43 II 0.21 15.00 44 II 0.43 24.95 9.59 217.8 2082 22.71 0.9610 45II 0.47 27.17 14.36 225.9 2396 15.73 0.9606 46 II 0.82 44.91 11.76 207.22350 17.62 0.9633 47 II 0.84 50.03 10.23 186.8 2111 18.25 0.9628 48 III<0.01 <0.01

The MWD of samples prepared using the different catalyst systemsdisclosed herein is presented in FIG. 1 while FIG. 2 provides a plot ofthe radius of gyration as a function of MW.

Example 2

Resins produced using a catalyst system of the type described hereinwere obtained and tested for their film performance. Particularly, twosets of BIP samples comprising polyethylene were prepared and designatedsamples 49-52. Samples 49 and 50 were prepared as a first set of BIPsamples while samples 51 and 52 were a second set of BIP samples thatwere prepared at a later date. Samples 53-59 comprised polyethyleneresins prepared using dissimilar catalyst systems. Specifically, sample53 was a commercial resin prepared using a Ziegler-Natta catalyst andhaving a melt index of 1; sample 54 was commercial resin prepared usinga conventional chromium catalyst system and having a melt index of 1;sample 55 was a commercial unimodal resin prepared using a Ziegler Nattacatalyst system and having a melt index of 2; samples 56 and 57 werecommercial resins prepared using a modified chromium catalyst system andhaving a melt index of 2 and 1, respectively; sample 58 was a multimodalresin having an MI of 2.81 and comprised 60% of a low molecular weight(LMW) component having a MW=26 kg/mol and 40% of a high molecular weight(HMW) component having a MW=220 kg/mol; and sample 59 was a multimodalresin having a MI of 1.2 and comprised 40% of a LMW component having aMW=20 kg/mol and 60% of a HMW component having a MW=220 kg/mol which hadbeen treated with peroxide to give a LCB value of 0.05 LCB/10,000 carbonatoms. GPC was conducted on samples 49-52 and a plot of these results isdepicted in FIGS. 3 and 4. The results demonstrate embodiments of BIPsof the type disclosed herein that are unimodal compositions having abroad MWD. Additional results of GPC analysis of the 11 samples testedare presented in Table 3.

TABLE 3 Sample M_(n) M_(w) M_(z) M_(w)/M_(n) No. kg/mol kg/mol kg/molkg/mol M_(z)/M_(w) 49 13 148 1357 11.4 9.2 50 15 154 1346 10.1 8.7 51 14148 1482 10.7 10.0 52 11 154 1680 13.6 10.9 53 22 140 704 6.2 5.0 54 18144 1083 8.0 7.5 55 18 115 437 6.3 3.8 56 15 135 1439 8.8 10.6 57 16 1531470 9.5 9.6 58 15 107 345 7.2 3.2 59 11 114 294 10.0 2.6

The results demonstrate samples 49 to 52 had a molecular weightdistribution in the range of those achieved with commercial chromiumcatalysts (samples 54, 56 and 58), implying that the ease of extrusionwould be similar to that of these commercial products.

The rheological behavior of samples 49-59 was also assessed and thoseresults are presented in Table 4.

TABLE 4 Sample E₀ τ₀ E@₁₀₀ Calculated No. Pa · s s a_0 Pa · s LCB/10000C 49 1.9E+04 0.020 0.2154 1.0E+03 0.029 50 1.9E+04 0.025 0.2368 1.2E+030.021 51 2.2E+04 0.017 0.1992 1.0E+03 0.032 52 5.1E+04 0.017 0.15411.0E+03 0.055 53 3.8E+04 0.182 0.2548 1.0E+03 0.066 54 9.5E+04 0.1470.1649 9.0E+02 0.127 55 1.1E+04 0.030 0.2977 9.6E+02 0.053 56 3.5E+040.047 0.1769 7.1E+02 0.070 57 7.0E+04 0.110 0.1707 8.5E+02 0.069 583.3E+03 0.022 0.5442 8.1E+02 0.016 59 8.9E+03 0.023 0.4196 1.7E+030.0474

The results demonstrate embodiments of BIPs of the type described herein(i.e., Samples 49-52) that have higher zero shear viscosity withoutimpacting too much the extrusion viscosity (Eta @ 100) over those oftypical bimodal resins such as samples 58 and 59, suggesting betterblown film bubble without an impact on output rates.

Barrier properties of the samples were also, assessed and these resultsare presented in Table 5.

TABLE 5 MVTR g · mil/100 Sample MI Density in²/day No. dg/min g/cc 1 mil49 1.2 0.965 0.5 50 1.0 0.964 0.56 51 1.2 0.965 0.38 52 1.1 0.965 0.3853 0.99 0.956 0.60 54 1.1 0.965 0.75 55 1.9 0.959 0.40 56 2.1 0.965 0.4857 1.3 0.964 0.58 58 2.8 0.965 0.40 59 1.2 0.963 0.45

The results demonstrate the homopolymer samples 51 and 52 achieved thelowest MVTR numbers at a melt index typical of a commercial applicationfor a similar film gauge. Further a plot of the MVTR as a function ofzero shear viscosity, FIG. 5, indicates that the samples would have ablown film bubble stability similar to some of the commercial resinswhile maintaining the MVTR advantage.

While embodiments of the invention have been shown and described,modifications thereof can be made by one skilled in the art withoutdeparting from the spirit and teachings of the invention. Theembodiments described herein are exemplary only, and are not intended tobe limiting. Many variations and modifications of the inventiondisclosed herein are possible and are within the scope of the invention.Where numerical ranges or limitations are expressly stated, such expressranges or limitations should be understood to include iterative rangesor limitations of like magnitude falling within the expressly statedranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4,etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example,whenever a numerical range with a lower limit, R₁, and an upper limit,R_(u), is disclosed, any number falling within the range is specificallydisclosed. In particular, the following numbers within the range arespecifically disclosed: R=R₁+k*(R_(u)−R₁), wherein k is a variableranging from 1 percent to 100 percent with a 1 percent increment, i.e.,k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . 50percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97percent, 98 percent, 99 percent, or 100 percent. Moreover, any numericalrange defined by two R numbers as defined in the above is alsospecifically disclosed. Use of the term “optionally” with respect to anyelement of a claim is intended to mean that the subject element isrequired, or alternatively, is not required. Both alternatives areintended to be within the scope of the claim. Use of broader terms suchas comprises, includes, having, etc., should be understood to providesupport for narrower terms such as consisting of, consisting essentiallyof, comprised substantially of, etc.

Accordingly, the scope of protection is not limited by the descriptionset out above but is only limited by the claims which follow, that scopeincluding all equivalents of the subject matter of the claims. Each andevery claim is incorporated into the specification as an embodiment ofthe present invention. Thus, the claims are a further description andare an addition to the embodiments of the present invention. Thediscussion of a herein is not an admission that it is prior art to thepresent invention, especially any reference that may have a publicationdate after the priority date of this application. The disclosures of allpatents, patent applications, and publications cited herein are herebyincorporated by reference, to the extent that they provide exemplary,procedural or other details supplementary to those set forth herein.

What is claimed is:
 1. A unimodal polyethylene resin having a density offrom about 0.946 g/ml to about 0.97 g/ml, a zero shear viscosity of fromabout 8×10² Pa-s to about 6×10⁴ Pa-s; a CY-a parameter of from about 0.5to about 0.6; a relaxation time of from about 0.01 s to about 0.10 s; apolydispersity index of from about 3 to about 120; and a long chainbranching (LCB) in an amount of from about 0.01 to about 0.5.
 2. Theresin of claim 1 having a weight average molecular weight (M_(w)) offrom about 10,000 g/mol to about 2,500,000 g/mol.
 3. The resin of claim1 having a number average molecular weight (M_(n)) of from about 3,000g/mol to about 150,000 g/mol.
 4. The resin of claim 1 having a meltindex of from about 0.01 g/10 min. to about 5.0 g/10 min.
 5. The resinof claim 1 having a E₁₀₀ of from about 8×10² Pa-s to about 2×10³ Pa-s.6. The resin of claim 1 having a density of greater than about 0.955g/ml.
 7. The resin of claim 1 having a LCB content of from 0.01 to about0.25.
 8. The resin of claim 1 having a polydispersity index of fromabout 4 to about
 80. 9. A film produced from the resin of claim
 1. 10.The film of claim 9 having a thickness of from about 0.3 mils to about3.0 mils.
 11. The film of claim 9 having a moisture vapor transmissionrate of from about 0.3 g.mil/100 in²/day to about 0.85 g.mil/100in²/day.
 12. A unimodal polyethylene resin having a density of fromabout 0.946 g/ml to about 0.97 g/ml; a CY-a parameter of from about 0.5to about 0.6; a relaxation time of from about 0.01 s to about 0.10 s; apolydispersity index of from about 3 to about 120; and a long chainbranching (LCB) in an amount of from about 0.01 to about 0.5.
 13. Theresin of claim 12 having a melt index of from about 0.01 g/10 min. toabout 5.0 g/10 min.
 14. The resin of claim 12 having a density ofgreater than about 0.955 g/ml.
 15. A film produced from the resin ofclaim
 12. 16. The resin of claim 12 having a LCB content of from 0.01 toabout 0.25.
 17. A method comprising: (a) providing a catalyst systemcomprising a half-sandwich transition metal complex; (b) contacting thecatalyst system with an olefin under conditions suitable to form apolyethylene; and (c) recovering the polyolefin, wherein thepolyethylene is unimodal and has a density of from about 0.946 g/ml toabout 0.97 g/ml and a zero shear viscosity of from about 8×10² Pa-s toabout 6×10⁴ Pa-s wherein the polyethylene has a CY-a parameter of fromabout 0.5 to about 0.6 a polydispersity index of from about 3 to about120; and a long chain branching (LCB) in an amount of from about 0.01 toabout 0.5.
 18. The method of claim 17 further comprising contacting thepolyethylene with peroxide after recovering the polyethylene.
 19. Themethod of claim 17 wherein a film formed from the polyolefin has amoisture vapor transmission rate of from about 0.3 g.mil/100 in²/day toabout 0.85 g.mil/100 in²/day.
 20. The method of claim 19 wherein thefilm has a thickness of from about 0.3 mils to about 3.0 mils.